diff --git a/figeno/gui/src/Basemod.jsx b/figeno/gui/src/Basemod.jsx
index 99b6c63..67cd5fa 100644
--- a/figeno/gui/src/Basemod.jsx
+++ b/figeno/gui/src/Basemod.jsx
@@ -209,7 +209,7 @@ export function BasemodfreqTrack({track,set_value,openColorPanel, setFileDialogD
             <div className="optionGroup">
 
                 <div className='formItem'>
-                    <label htmlFor={"style"+track.id}>Style:</label>
+                    <label title="Style for the track. Lines is the default and will show lines connecting the values for each sample. Dots is recommended if the data is sparse, and will show a dot for each value." htmlFor={"style"+track.id}>Style:</label>
                     <select id={"style"+track.id} value={track.style} onChange={(e) =>{set_value("style",e.target.value)}}> 
                             <option className="dropDownOption" key="default" value="lines">lines</option>
                             <option className="dropDownOption" key="dots" value="dots">dots</option>
@@ -219,11 +219,11 @@ export function BasemodfreqTrack({track,set_value,openColorPanel, setFileDialogD
                 {(track.style=="lines")?(
                 <>
                     <div className='formItem'>
-                        <label htmlFor={"smooth"+track.id}>Smooth:</label>
+                        <label title="If 0, will simply use the raw base modification frequency at each position. If x>0, will average with the next x and previous x positions." htmlFor={"smooth"+track.id}>Smooth:</label>
                         <input id={"smooth"+track.id} style={{width:"3em"}} value={track.smooth} onChange={(e) => set_value("smooth",e.target.value)}/>
                     </div>
                     <div className='formItem'>
-                        <label htmlFor={"gap_frac"+track.id}>gap_frac:</label>
+                        <label title="If two values are separated by a distance > grap_frac * region_size, they won't be connected by a line. This is meant to avoid straight lines in case there is a large region with no values." htmlFor={"gap_frac"+track.id}>gap_frac:</label>
                         <input id={"gap_frac"+track.id} style={{width:"3em"}} value={track.gap_frac} onChange={(e) => set_value("gap_frac",e.target.value)}/>
                     </div>
                 </>
diff --git a/figeno/gui/src/Track.jsx b/figeno/gui/src/Track.jsx
index fdffcda..4e07693 100644
--- a/figeno/gui/src/Track.jsx
+++ b/figeno/gui/src/Track.jsx
@@ -65,31 +65,31 @@ export function Track({track, set_value, change_track_type, copy_track, delete_t
                 {track.type!=""?(
                 <div className="optionGroup">
                     <div className='formItem'>
-                    <label htmlFor={"height"+track.id}>Height (mm):</label>
+                    <label title="Height of the track, in mm." htmlFor={"height"+track.id}>Height (mm):</label>
                     <input id={"height"+track.id} value ={track.height} style={{width:"3em"}} onChange={(e) => set_value("height",e.target.value)}></input>
                     </div>
 
                     <div className='formItem'>
-                        <label htmlFor={"margin_above"+track.id}>Margin above:</label>
+                        <label title="Margin above the track, in mm." htmlFor={"margin_above"+track.id}>Margin above:</label>
                         <input id={"margin_above"+track.id} value ={track.margin_above} style={{width:"2em"}} onChange={(e) => set_value("margin_above",e.target.value)}></input>
                     </div>
 
                     <div className='formItem'>
-                        <label htmlFor={"bounding_box"+track.id}>Box:</label>
+                        <label title="If true, draw a bounding box around the track." htmlFor={"bounding_box"+track.id}>Box:</label>
                         <input type="checkbox" id={"bounding_box"+track.id} checked={track.bounding_box} onChange={() => set_value("bounding_box",!track.bounding_box)}/>
                     </div>
 
                     <div className='formItem'>
-                        <label htmlFor={"fontscale"+track.id}>Fontscale:</label>
+                        <label title="Scale for the font. Values < 1 will result in a smaller fontsize." htmlFor={"fontscale"+track.id}>Fontscale:</label>
                         <input id={"fontscale"+track.id} value ={track.fontscale} style={{width:"2em"}} onChange={(e) => set_value("fontscale",e.target.value)}></input>
                     </div>
 
                     <div className='formItem'>
-                        <label htmlFor={"label"+track.id}>Label:</label>
+                        <label title="Label for the track, shown on the left." htmlFor={"label"+track.id}>Label:</label>
                         <input id={"label"+track.id} style={{width:"10em"}} value={track.label}  onChange={(e) => set_value("label",e.target.value)} ></input>
                     </div>
                     <div className='formItem'>
-                        <label htmlFor={"label_rotate"+track.id}>Rotate label:</label>
+                        <label title="If false, the label is written horizontally. If true, it is written vertically." htmlFor={"label_rotate"+track.id}>Rotate label:</label>
                         <input type="checkbox" id={"label_rotate"+track.id} checked={track.label_rotate} onChange={() => set_value("label_rotate",!track.label_rotate)} ></input>
                     </div>
                 </div>
@@ -111,7 +111,7 @@ function ChrTrack({track,set_value}){
         <>
         <div className="optionGroup">
             <div className='formItem'>
-                <label htmlFor={"style"+track.id}>Style:</label>
+                <label title="Style for the axis:&#10;default: show a horizontal line with regular ticks.&#10;arrow: show a colored arrow, with coordinates at each end of the region (recommended when multiple regions are displayed).&#10;ideogram: ideogram of the chromosome, with a red box highlighting where the region lies within the chromosome." htmlFor={"style"+track.id}>Style:</label>
                 <select id={"style"+track.id} value={track.style} onChange={(e) =>{set_value("style",e.target.value)}}> 
                             <option className="dropDownOption" key="default" value="default">default</option>
                             <option className="dropDownOption" key="arrow" value="arrow">arrow</option>
@@ -119,14 +119,14 @@ function ChrTrack({track,set_value}){
                 </select>
             </div>
             <div className='formItem'>
-                <label htmlFor={"lw_scale"+track.id}>lw_scale:</label>
+                <label title="Scale for the linewidth. Lower values will result in a thinner line for the axis." htmlFor={"lw_scale"+track.id}>lw_scale:</label>
                 <input id={"lw_scale"+track.id} style={{width:"3em"}} value={track.lw_scale}  onChange={(e)=>set_value("lw_scale",e.target.value)} ></input>
             </div>
         </div>
 
         <div className="optionGroup">
             <div className='formItem'>
-                <label htmlFor={"ticklabels_pos"+track.id}>Tick labels position:</label>
+                <label title="Indicate whether the tick labels should be above or below the axis.&#10;Use 'below' if this track is located at the bottom of the figure, and 'above' if it is located at the top." htmlFor={"ticklabels_pos"+track.id}>Tick labels position:</label>
                 <select id={"ticklabels_pos"+track.id} value={track.ticklabels_pos} onChange={(e) =>{set_value("ticklabels_pos",e.target.value)}}> 
                             <option className="dropDownOption" key="below" value="below">below</option>
                             <option className="dropDownOption" key="above" value="above">above</option>
@@ -136,7 +136,7 @@ function ChrTrack({track,set_value}){
             {(track.ticklabels_pos!="none")?(
             <>
             <div className='formItem'>
-                <label htmlFor={"unit"+track.id}>Unit:</label>
+                <label title="Unit for the genomic coordinates." htmlFor={"unit"+track.id}>Unit:</label>
                 <select id={"unit"+track.id} value={track.unit} onChange={(e) =>{set_value("unit",e.target.value)}}> 
                             <option className="dropDownOption" key="bp" value="bp">bp</option>
                             <option className="dropDownOption" key="kb" value="kb">kb</option>
@@ -145,15 +145,15 @@ function ChrTrack({track,set_value}){
             </div>
             
             <div className='formItem'>
-                <label htmlFor={"ticks_interval"+track.id}>Ticks interval (bp):</label>
+                <label title="Number of base pairs between each tick. If 'auto', will automatically select an appropriate value." htmlFor={"ticks_interval"+track.id}>Ticks interval (bp):</label>
                 <input id={"ticks_interval"+track.id} style={{width:"4em"}} value={track.ticks_interval}  onChange={(e)=>set_value("ticks_interval",e.target.value)} ></input>
             </div>
             <div className='formItem'>
-                <label htmlFor={"ticks_angle"+track.id}>Ticks angle (°):</label>
+                <label title="Rotation for the ticks label, which might be helpful if they are dense." htmlFor={"ticks_angle"+track.id}>Ticks angle (°):</label>
                 <input id={"ticks_angle"+track.id} style={{width:"3em"}} value={track.ticks_angle}  onChange={(e)=>set_value("ticks_angle",e.target.value)} ></input>
             </div>
             <div className='formItem'>
-                <label htmlFor={"chr_prefix"+track.id}>Chr prefix:</label>
+                <label title="Prefix to add before the chromosome name." htmlFor={"chr_prefix"+track.id}>Chr prefix:</label>
                 <input id={"chr_prefix"+track.id} style={{width:"3em"}} value={track.chr_prefix}  onChange={(e)=>set_value("chr_prefix",e.target.value)} ></input>
             </div> 
             </>):""}
@@ -168,7 +168,7 @@ function GenesTrack({track,set_value,openColorPanel}){
         <>
         <div className="optionGroup">
             <div className='formItem'>
-                <label htmlFor={"style"+track.id}>Style:</label>
+                <label title="Style for the track.&#10;default will show genes on multiple lines, where the last exon has an arrow indicating the orientation.&#10;TSS_arrow is recommended if you only show one gene: it will display an arrow above the gene, at the transcription start site, indicating the orientation." htmlFor={"style"+track.id}>Style:</label>
                 <select id={"style"+track.id} value={track.style} onChange={(e) =>{set_value("style",e.target.value)}}> 
                             <option className="dropDownOption" key="default" value="default">default</option>
                             <option className="dropDownOption" key="TSS_arrow" value="TSS_arrow">TSS_arrow</option>
@@ -176,17 +176,17 @@ function GenesTrack({track,set_value,openColorPanel}){
             </div>
 
             <div className='formItem'>
-                <label htmlFor={"collapsed"+track.id}>Collapsed:</label>
+                <label title="If true, will display all transcripts for a gene together (on the same row). Otherwise, show each transcript on a different line." htmlFor={"collapsed"+track.id}>Collapsed:</label>
                 <input type="checkbox" id={"collapsed"+track.id} checked={track.collapsed} onChange={() => set_value("collapsed",!track.collapsed)} ></input>
             </div>
 
             <div className='formItem'>
-                <label htmlFor={"only_protein_coding"+track.id}>Only protein coding:</label>
+                <label title="If true, only display protein coding genes." htmlFor={"only_protein_coding"+track.id}>Only protein coding:</label>
                 <input type="checkbox" id={"only_protein_coding"+track.id} checked={track.only_protein_coding} onChange={() => set_value("only_protein_coding",!track.only_protein_coding)} ></input>
             </div>
 
             <div className='formItem' >
-                <label htmlFor={"exon_color"+track.id}>Exon color:</label>
+                <label title="Color for the exons." htmlFor={"exon_color"+track.id}>Exon color:</label>
                 <ColorButton id={"exon_color"+track.id} color={track.exon_color} setColor={(c)=>set_value("exon_color",c)} openColorPanel={openColorPanel}/>
             </div>
 
@@ -194,12 +194,12 @@ function GenesTrack({track,set_value,openColorPanel}){
         </div>
         <div className="optionGroup">
             <div className='formItem'>
-                <label htmlFor={"genes"+track.id}>Genes:</label>
+                <label title="Comma-separated list of names of genes to display. If 'auto', will show all genes in the region." htmlFor={"genes"+track.id}>Genes:</label>
                 <input id={"genes"+track.id} value={track.genes}  onChange={(e) => set_value("genes",e.target.value)} ></input>
             </div>
 
             <div className='formItem'>
-                <label htmlFor={"show_gene_names"+track.id}>Show gene names:</label>
+                <label title="Show the name of each gene. When displaying large regions with many genes, you may want to disable this option." htmlFor={"show_gene_names"+track.id}>Show gene names:</label>
                 <input type="checkbox" id={"show_gene_names"+track.id} checked={track.show_gene_names} onChange={() => set_value("show_gene_names",!track.show_gene_names)} ></input>
             </div>
         </div>
@@ -214,9 +214,9 @@ function BedTrack({track,set_value,openColorPanel, setFileDialogData,setFileDial
     return (
         <>
         <div className="optionGroup">
-            <PathEntry id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass} setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive}/>
+            <PathEntry title="Path to the bed file. The first three columns must be chr start end." id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass} setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive}/>
             <div className='formItem'>
-                <label htmlFor={"use_file_colors"+track.id}>Use file colors: </label>
+                <label title="Use colors provided in the ninth column of the bed file.&#013;If not selected, will use a custom color for all intervals." htmlFor={"use_file_colors"+track.id}>Use file colors: </label>
                 <input type="checkbox" id={"use_file_colors"+track.id} checked={track.use_file_colors} onChange={() => set_value("use_file_colors",!track.use_file_colors)} ></input>
             </div>
             {(!track.use_file_colors)?(
@@ -227,15 +227,15 @@ function BedTrack({track,set_value,openColorPanel, setFileDialogData,setFileDial
             }
             
             <div className='formItem'>
-                <label htmlFor={"show_names"+track.id}>Show names:</label>
+                <label title="Show the name of each interval (fourth column in the bed file)." htmlFor={"show_names"+track.id}>Show names:</label>
                 <input type="checkbox" id={"show_names"+track.id} checked={track.show_names} onChange={() => set_value("show_names",!track.show_names)} ></input>
             </div>
             <div className='formItem'>
-                <label htmlFor={"show_strand"+track.id}>Show strand:</label>
+                <label title="Show arrows indicating the strand of the interval ('+' or '-', in the sixth column of the bed file)." htmlFor={"show_strand"+track.id}>Show strand:</label>
                 <input type="checkbox" id={"show_strand"+track.id} checked={track.show_strand} onChange={() => set_value("show_strand",!track.show_strand)} ></input>
             </div>
             <div className='formItem'>
-                <label htmlFor={"collapsed"+track.id}>Collapsed:</label>
+                <label title="If ticked, will show all intervals on the same row. Otherwise, use multiple rows to avoid overlaps." htmlFor={"collapsed"+track.id}>Collapsed:</label>
                 <input type="checkbox" id={"collapsed"+track.id} checked={track.collapsed} onChange={() => set_value("collapsed",!track.collapsed)} ></input>
             </div>
             
@@ -252,19 +252,19 @@ function BigWigTrack({track,set_value,openColorPanel, setFileDialogData,setFileD
         <>
         
             <div className="optionGroup">
-                <PathEntry id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass}  setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive}/>
+                <PathEntry title="Path to the bigwig file" id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass}  setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive}/>
                 <div className='formItem' >
-                    <label htmlFor={"color"+track.id}>Color:</label>
+                    <label title="Color of the track." htmlFor={"color"+track.id}>Color:</label>
                     <ColorButton id={"color"+track.id} color={track.color} setColor={(c)=>set_value("color",c)} openColorPanel={openColorPanel}></ColorButton>
                 </div>
                 <div className='formItem'>
-                    <label className="withTooltip" htmlFor={"nbins"+track.id}>n_bins:</label>
+                    <label title="Number of bins (intervals within which the signal in the bigwig file will be averaged)" htmlFor={"nbins"+track.id}>n_bins:</label>
                     <input id={"nbins"+track.id} value={track.n_bins}  onChange={(e) => set_value("n_bins",e.target.value)} ></input>
                 </div>
 
                 {/* scale */}
                 <div className='formItem'>
-                    <label htmlFor={"scale"+track.id}>Scale:</label>
+                    <label title="How to set the maximum value for the y-axis." htmlFor={"scale"+track.id}>Scale:</label>
                     <select id={"scale"+track.id} value={track.scale} onChange={(e) =>{set_value("scale",e.target.value)}}> 
                                 <option className="dropDownOption" key="auto" value="auto">auto</option>
                                 <option className="dropDownOption" key="group auto" value="group auto">group auto</option>
@@ -281,13 +281,13 @@ function BigWigTrack({track,set_value,openColorPanel, setFileDialogData,setFileD
                 }
                 {(track.scale=="group auto" || track.scale=="group auto per region")?(
                     <div className='formItem'>
-                    <label htmlFor={"group"+track.id}>Group:</label>
+                    <label title="Group for this track. All tracks of the same group and with the scale 'per region' will have the same scale." htmlFor={"group"+track.id}>Group:</label>
                     <input id={"group"+track.id} style={{width:"3em"}} value={track.group} onChange={(e) => set_value("group",e.target.value)} ></input>
                 </div>):""
                 }
 
                 <div className='formItem'>
-                    <label htmlFor={"scale_pos"+track.id}>Scale pos:</label>
+                    <label title="Position of the scale:&#10;left: on the left of the track.&#10;corner: in the top-left corner of the track, for the first region.&#10;corner all: in the top-left corner of the track, for each region.&#10;none: do not display the scale." htmlFor={"scale_pos"+track.id}>Scale pos:</label>
                     <select id={"scale_pos"+track.id} value={track.scale_pos} onChange={(e) =>{set_value("scale_pos",e.target.value)}}> 
                                 <option className="dropDownOption" key="left" value="left">left</option>
                                 <option className="dropDownOption" key="corner" value="corner">corner</option>
@@ -297,7 +297,7 @@ function BigWigTrack({track,set_value,openColorPanel, setFileDialogData,setFileD
                 </div>
 
                 <div className='formItem'>
-                    <label htmlFor={"upside_down"+track.id}>Upside down:</label>
+                    <label title="If true, plot the track upside down (high values at the bottom)." htmlFor={"upside_down"+track.id}>Upside down:</label>
                     <input type="checkbox" id={"upside_down"+track.id} checked={track.upside_down} onChange={() => set_value("upside_down",!track.upside_down)} />
                 </div>
 
@@ -312,18 +312,18 @@ function CoverageTrack({track,set_value,openColorPanel, setFileDialogData,setFil
     return (
         <>
             <div className="optionGroup">
-            <PathEntry id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass} setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive}/>
+            <PathEntry title="Path to the bam file (must be indexed)." id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass} setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive}/>
                 <div className='formItem' >
-                    <label htmlFor={"color"+track.id}>Color:</label>
+                    <label title="Color for the track." htmlFor={"color"+track.id}>Color:</label>
                     <ColorButton id={"color"+track.id} color={track.color} setColor={(c)=>set_value("color",c)} openColorPanel={openColorPanel}></ColorButton>
                 </div>
                 <div className='formItem'>
-                    <label className="withTooltip" htmlFor={"nbins"+track.id}>n_bins:</label>
+                    <label title="Number of bins (intervals within which the coverage will be averaged)" htmlFor={"nbins"+track.id}>n_bins:</label>
                     <input id={"nbins"+track.id} value={track.n_bins}  onChange={(e) => set_value("n_bins",e.target.value)} ></input>
                 </div>
 
                 <div className='formItem'>
-                    <label htmlFor={"scale"+track.id}>Scale:</label>
+                    <label title="How to set the maximum value for the y-axis." htmlFor={"scale"+track.id}>Scale:</label>
                     <select id={"scale"+track.id} value={track.scale} onChange={(e) =>{set_value("scale",e.target.value)}}> 
                                 <option className="dropDownOption" key="auto" value="auto">auto</option>
                                 <option className="dropDownOption" key="group auto" value="group auto">group auto</option>
@@ -345,7 +345,7 @@ function CoverageTrack({track,set_value,openColorPanel, setFileDialogData,setFil
                 </div>):""
                 }
                 <div className='formItem'>
-                    <label htmlFor={"scale_pos"+track.id}>Scale pos:</label>
+                    <label  title="Position of the scale:&#10;left: on the left of the track.&#10;corner: in the top-left corner of the track, for the first region.&#10;corner all: in the top-left corner of the track, for each region.&#10;none: do not display the scale." htmlFor={"scale_pos"+track.id}>Scale pos:</label>
                     <select id={"scale_pos"+track.id} value={track.scale_pos} onChange={(e) =>{set_value("scale_pos",e.target.value)}}> 
                                 <option className="dropDownOption" key="left" value="left">left</option>
                                 <option className="dropDownOption" key="corner" value="corner">corner</option>
@@ -355,7 +355,7 @@ function CoverageTrack({track,set_value,openColorPanel, setFileDialogData,setFil
                 </div>
 
                 <div className='formItem'>
-                    <label htmlFor={"upside_down"+track.id}>Upside down:</label>
+                    <label title="If true, plot the track upside down (high values at the bottom)." htmlFor={"upside_down"+track.id}>Upside down:</label>
                     <input type="checkbox" id={"upside_down"+track.id} checked={track.upside_down} onChange={() => set_value("upside_down",!track.upside_down)} />
                 </div>
 
@@ -404,20 +404,20 @@ function AlignmentsTrack({track,set_value,openColorPanel, setFileDialogData,setF
     return (
         <>
         <div className="optionGroup">
-            <PathEntry id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass}  setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive} />
+            <PathEntry title="Path to the bam file (must be indexed)." id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass}  setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive} />
             <div className='formItem'>
-                <label htmlFor={"hgap_bp"+track.id}>h-gap (bp):</label>
+                <label title="Minimum number of base pairs between two reads for them to be displayed on the same row." htmlFor={"hgap_bp"+track.id}>h-gap (bp):</label>
                 <input id={"hgap_bp"+track.id} style={{width:"2em"}} value={track.hgap_bp}  onChange={(e)=>set_value("hgap_bp",e.target.value)} ></input>
             </div>
 
             <div className='formItem'>
-                <label htmlFor={"vgap_frac"+track.id}>v-gap (frac):</label>
+                <label title="Fraction of the vertical space to leave empty. Setting this value to 1 will result in reads from different rows to be next to each other." htmlFor={"vgap_frac"+track.id}>v-gap (frac):</label>
                 <input id={"vgap_frac"+track.id} style={{width:"2em"}} value={track.vgap_frac}  onChange={(e)=>set_value("vgap_frac",e.target.value)} ></input>
             </div>
 
 
             <div className='formItem' >
-                <label htmlFor={"read_color"+track.id}>Read color:</label>
+                <label title="Color for the reads." htmlFor={"read_color"+track.id}>Read color:</label>
                 <ColorButton id={"read_color"+track.id} color={track.read_color} setColor={(c)=>set_value("read_color",c)} openColorPanel={openColorPanel}/>
             </div>
         </div>
@@ -426,29 +426,29 @@ function AlignmentsTrack({track,set_value,openColorPanel, setFileDialogData,setF
         <div className="optionGroup">
 
             <div className='formItem'>
-                <label htmlFor={"link_splitreads"+track.id}>Link splitreads:</label>
+                <label title="If true, will display a dashed line connecting several alignments of the same split read (even if they are in different regions)." htmlFor={"link_splitreads"+track.id}>Link splitreads:</label>
                 <input type="checkbox" id={"link_splitreads"+track.id} checked={track.link_splitreads} onChange={() => set_value("link_splitreads",!track.link_splitreads)} ></input>
             </div>
             {track.link_splitreads ? (<>
                  <div className='formItem'>
-                    <label htmlFor={"only_show_splitreads"+track.id}>Only show SR:</label>
+                    <label title="If true, will only display split reads" htmlFor={"only_show_splitreads"+track.id}>Only show SR:</label>
                     <input type="checkbox" id={"lonly_show_splitreads"+track.id} checked={track.only_show_splitreads} onChange={() => set_value("only_show_splitreads",!track.only_show_splitreads)} ></input>
                 </div>
                 <div className='formItem' >
-                    <label htmlFor={"splitread_color"+track.id}>Splitread color:</label>
+                    <label title="Color of the split reads (if you want to highlight them)." htmlFor={"splitread_color"+track.id}>Splitread color:</label>
                     <ColorButton id={"splitread_color"+track.id} color={track.splitread_color} setColor={(c)=>set_value("splitread_color",c)} openColorPanel={openColorPanel}/>
                 </div>
                 <div className='formItem' >
-                    <label htmlFor={"link_color"+track.id}>Link color:</label>
+                    <label title="Color of the dashed line connecting split reads." htmlFor={"link_color"+track.id}>Link color:</label>
                     <ColorButton id={"link_color"+track.id} color={track.link_color} setColor={(c)=>set_value("link_color",c)} openColorPanel={openColorPanel}/>
                 </div>
                 <div className='formItem'>
-                    <label htmlFor={"link_lw"+track.id}>Link lw: </label>
+                    <label title="Width of the dashed line connecting split reads." htmlFor={"link_lw"+track.id}>Link lw: </label>
                     <input id={"link_lw"+track.id} style={{width:"2.1em"}} value={track.link_lw}  onChange={(e)=>set_value("link_lw",e.target.value)} />
                 </div>
 
                 <div className='formItem'>
-                    <label className="withTooltip" htmlFor={"min_splitreads_breakpoints"+track.id}>Min SR: <span className="tooltip">Minimum number of split reads spanning a breakpoint for this breakpoint to be shown.</span></label>
+                    <label title="Minimum number of split reads spanning a breakpoint for this breakpoint to be shown." htmlFor={"min_splitreads_breakpoints"+track.id}>Min SR: </label>
                     <input id={"min_splitreads_breakpoints"+track.id} style={{width:"1em"}} value={track.min_splitreads_breakpoints}  onChange={(e)=>set_value("min_splitreads_breakpoints",e.target.value)} />
                 </div>
                 
@@ -460,7 +460,7 @@ function AlignmentsTrack({track,set_value,openColorPanel, setFileDialogData,setF
         {/* Group by*/}
         <div className="optionGroup">
             <div className='formItem'>
-                <label htmlFor={"group_by"+track.id}>Group by:</label>
+                <label title="Whether to group reads by haplotype. This requires the reads to have an 'HP' tag in the bam file, for example added by whatshap." htmlFor={"group_by"+track.id}>Group by:</label>
                 <select id={"group_by"+track.id} value={track.group_by} onChange={handleGroupbyChange}> 
                             <option className="dropDownOption" key="none" value="none">none</option>
                             <option className="dropDownOption" key="haplotype" value="haplotype">haplotype</option>
@@ -469,28 +469,28 @@ function AlignmentsTrack({track,set_value,openColorPanel, setFileDialogData,setF
             {(track.group_by=="haplotype")?(
                 <>
                 <div className='formItem'>
-                    <label htmlFor={"show_unphased"+track.id}>Show unphased:</label>
+                    <label title="Whether or not to also show unphased reads (which do not have an HP tag)." htmlFor={"show_unphased"+track.id}>Show unphased:</label>
                     <input type="checkbox" id={"show_unphased"+track.id} checked={track.show_unphased} onChange={() => set_value("show_unphased",!track.show_unphased)} ></input>
                 </div>
 
                 <div className='formItem'>
-                    <label htmlFor={"exchange_haplotypes"+track.id}>Exchange haplotypes:</label>
+                    <label title="If true, will show the second haplotype at the top." htmlFor={"exchange_haplotypes"+track.id}>Exchange haplotypes:</label>
                     <input type="checkbox" id={"exchange_haplotypes"+track.id} checked={track.exchange_haplotypes} onChange={() => set_value("exchange_haplotypes",!track.exchange_haplotypes)} ></input>
                 </div>
 
                 <div className='formItem'>
-                    <label htmlFor={"show_haplotype_colors"+track.id}>Show haplotype colors:</label>
+                    <label title="If true, will add a colored rectangle for each group." htmlFor={"show_haplotype_colors"+track.id}>Show haplotype colors:</label>
                     <input type="checkbox" id={"show_haplotype_colors"+track.id} checked={track.show_haplotype_colors} onChange={() => set_value("show_haplotype_colors",!track.show_haplotype_colors)} ></input>
                 </div>
 
                 <div className='formItem'>
-                    <label htmlFor={"labelHaplo1"+track.id}>Haplotype 1:</label>
+                    <label title="Label for the first haplotype." htmlFor={"labelHaplo1"+track.id}>Haplotype 1:</label>
                     <input id={"labelHaplo1"+track.id} style={{width:"6em"}} value={track.haplotype_labels[0]}  onChange={(e)=>setHaplotypeLabel(e,0)} ></input>
                         {track.show_haplotype_colors?(<ColorButton id={"colorHaplo1"+track.id} color={track.haplotype_colors[0]} setColor={(c)=>setHaplotypeColors(c,0)} openColorPanel={openColorPanel}></ColorButton>
                         ):""}
                 </div>
                 <div className='formItem'>
-                    <label htmlFor={"labelHaplo2"+track.id}>Haplotype 2:</label>
+                    <label title="Label for the first haplotype." htmlFor={"labelHaplo2"+track.id}>Haplotype 2:</label>
                     <input id={"labelHaplo2"+track.id} style={{width:"6em"}} value={track.haplotype_labels[1]}  onChange={(e)=>setHaplotypeLabel(e,1)} ></input>
                         {track.show_haplotype_colors?(<ColorButton id={"colorHaplo2"+track.id} color={track.haplotype_colors[1]} setColor={(c)=>setHaplotypeColors(c,1)} openColorPanel={openColorPanel}></ColorButton>
                         ):""}
@@ -499,7 +499,7 @@ function AlignmentsTrack({track,set_value,openColorPanel, setFileDialogData,setF
                 <div className='formItem'>
                     {track.show_unphased?(
                     <>
-                    <label htmlFor={"labelHaplo3"+track.id}>Unphased:</label>
+                    <label title="Label for the unphased reads." htmlFor={"labelHaplo3"+track.id}>Unphased:</label>
                     <input id={"labelHaplo3"+track.id} style={{width:"6em"}} value={track.haplotype_labels[2]}  onChange={(e)=>setHaplotypeLabel(e,2)} />
                     </>):""}
                     {(track.show_haplotype_colors&&track.show_unphased)?(
@@ -513,7 +513,7 @@ function AlignmentsTrack({track,set_value,openColorPanel, setFileDialogData,setF
         {/* Color by*/}
         <div className='optionGroup'>
             <div className='formItem'>
-                <label htmlFor={"color_by"+track.id}>Color by:</label>
+                <label title="Whether to color reads according to their base modifications (e.g. methylation) or not." htmlFor={"color_by"+track.id}>Color by:</label>
                 <select id={"color_by"+track.id} value={track.color_by} onChange={(e)=>set_value("color_by",e.target.value)}> 
                             <option className="dropDownOption" key="none" value="none">none</option>
                             <option className="dropDownOption" key="basemod" value="basemod">basemod</option>
@@ -522,31 +522,31 @@ function AlignmentsTrack({track,set_value,openColorPanel, setFileDialogData,setF
             {(track.color_by=="basemod")?(
                 <>
                 <div className='formItem'>
-                    <label htmlFor={"color_unmodified"+track.id}>Unmodified:</label>
+                    <label title="Color for the unmodified bases (e.g. unmethylated)." htmlFor={"color_unmodified"+track.id}>Unmodified:</label>
                     <ColorButton id={"color_unmodified"+track.id} color={track.color_unmodified} setColor={(c)=>set_value("color_unmodified",c)} openColorPanel={openColorPanel}/>
                 </div>
 
                 <div className='formItem'>
-                    <label htmlFor={"base1"+track.id}>Basemod 1:</label>
+                    <label title="First base modification. You have to specify the base (e.g. C for CpG methylation), then the modification itself (e.g. m for methylation, h for hydroxymethylation), and the color)." htmlFor={"base1"+track.id}>Basemod 1:</label>
                     <input id={"base1"+track.id} style={{width:"1em"}} value={track.basemods[0][0]}  onChange={(e)=>setBasemod(0,0,e.target.value)}/>
                     <input id={"mod1"+track.id} style={{width:"1em"}} value={track.basemods[0][1]}  onChange={(e)=>setBasemod(0,1,e.target.value)}/>
                     <ColorButton id={"color_basemod1"+track.id} color={track.basemods[0][2]} setColor={(c)=>setBasemod(0,2,c)} openColorPanel={openColorPanel}/>
                 </div>
-                {track.basemods.length==1? (<button onClick={addBasemod}>Add basemod</button>):""}
+                {track.basemods.length==1? (<button title="Click to visualize a second basemodification." onClick={addBasemod}>Add basemod</button>):""}
                 {track.basemods.length==2? (
                 <>
                 <div className='formItem'>
-                    <label htmlFor={"base2"+track.id}>Basemod 2:</label>
+                    <label  title="Second base modification. You have to specify the base (e.g. C for CpG methylation), then the modification itself (e.g. m for methylation, h for hydroxymethylation), and the color)." htmlFor={"base2"+track.id}>Basemod 2:</label>
                     <input id={"base2"+track.id} style={{width:"1em"}} value={track.basemods[1][0]}  onChange={(e)=>setBasemod(1,0,e.target.value)}/>
                     <input id={"mod2"+track.id} style={{width:"1em"}} value={track.basemods[1][1]}  onChange={(e)=>setBasemod(1,1,e.target.value)}/>
                     <ColorButton id={"color_basemod2"+track.id} color={track.basemods[1][2]} setColor={(c)=>setBasemod(1,2,c)} openColorPanel={openColorPanel}/>
                 </div>
-                <button onClick={deleteBasemod}>Delete basemod</button>
+                <button title="Click to only visualize one base modification." onClick={deleteBasemod}>Delete basemod</button>
                 
                 </>
                 ):""}
                 <div className='formItem'>
-                    <label htmlFor={"fix_hardclip_basemod"+track.id}>Fix hardclip basemod:</label>
+                    <label title="Most aligners use hardclipping by default for supplementary alignments, which make the base modification calls unusable for supplementary alignments. If true, will try to recover the original sequence from the primary alignment, which should enable the visualization of base modifications also for supplementary alignments." htmlFor={"fix_hardclip_basemod"+track.id}>Fix hardclip basemod:</label>
                     <input type="checkbox" id={"fix_hardclip_basemod"+track.id} checked={track.fix_hardclip_basemod} onChange={() => set_value("fix_hardclip_basemod",!track.fix_hardclip_basemod)} ></input>
                 </div>
 
@@ -566,9 +566,9 @@ function HicTrack({track,set_value, setFileDialogData,setFileDialogActive}){
     return (
         <>
         <div className="optionGroup">
-            <PathEntry id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass}  setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive} />
+            <PathEntry title="Path to the file containing the HiC data, in .cool or .mcool format." id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass}  setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive} />
             <div className='formItem'>
-                <label htmlFor={"color_map"+track.id}>Color map:</label>
+                <label title="Which color map to use (mapping of contact frequencies to color)." htmlFor={"color_map"+track.id}>Color map:</label>
                 <select id={"color_map"+track.id} value={track.color_map} onChange={(e) =>{set_value("color_map",e.target.value)}}> 
                             <option className="dropDownOption" key="red" value="red">red</option>
                             <option className="dropDownOption" key="heat" value="heat">heat</option>
@@ -576,7 +576,7 @@ function HicTrack({track,set_value, setFileDialogData,setFileDialogActive}){
             </div>
 
             <div className='formItem'>
-                <label htmlFor={"scale"+track.id}>Scale:</label>
+                <label title="How to set the minimum and maximum values for the colormap." htmlFor={"scale"+track.id}>Scale:</label>
                 <select id={"scale"+track.id} value={track.scale} onChange={(e) =>{set_value("scale",e.target.value)}}> 
                             <option className="dropDownOption" key="auto" value="auto">auto</option>
                             <option className="dropDownOption" key="custom"  value="custom">custom</option>
@@ -594,13 +594,13 @@ function HicTrack({track,set_value, setFileDialogData,setFileDialogActive}){
                     </div>
                     </>):(
                         <div className='formItem'>
-                        <label htmlFor={"scale_max_percentile"+track.id}>Max percentile:</label>
+                        <label title="For the scale, will use this percentile for the maximum of the colormap (e.g. if it is set to 90, then the 10% points with highest values will all have the same color. Setting this <100 generally results in a nicer visualization)." htmlFor={"scale_max_percentile"+track.id}>Max percentile:</label>
                         <input id={"scale_max_percentile"+track.id} style={{width:"3em"}} value={track.scale_max_percentile} onChange={(e) => set_value("scale_max_percentile",e.target.value)} ></input>
                         </div>
                     )
                 }
             <div className='formItem'>
-                <label htmlFor={"show_colorbar"+track.id}>Show colorbar:</label>
+                <label title="If true, will show a colorbar indicating the mapping from values to colors." htmlFor={"show_colorbar"+track.id}>Show colorbar:</label>
                 <input type="checkbox" id={"show_colorbar"+track.id} checked={track.show_colorbar} onChange={() => set_value("show_colorbar",!track.show_colorbar)} />
             </div>
             
@@ -609,30 +609,30 @@ function HicTrack({track,set_value, setFileDialogData,setFileDialogActive}){
         <div className="optionGroup">
 
             <div className='formItem'>
-                <label htmlFor={"max_dist"+track.id}>Max dist (kb):</label>
+                <label title="Maximum distance between two regions for their interaction to be shown." htmlFor={"max_dist"+track.id}>Max dist (kb):</label>
                 <input id={"max_dist"+track.id} style={{width:"4em"}} value={track.max_dist}  onChange={(e) => set_value("max_dist",e.target.value)} />
             </div>
 
             <div className='formItem'>
-                <label htmlFor={"extend"+track.id}>Extend:</label>
+                <label title="If false, only show pixels corresponding to interactions where both sides are within the displayed regions. If true, will also show interactions where only one side is within the displayed regions, which will result in the track to look like a rectangle without unused space." htmlFor={"extend"+track.id}>Extend:</label>
                 <input type="checkbox" id={"extend"+track.id} checked={track.extend} onChange={() => set_value("extend",!track.extend)} />
             </div>
             <div className='formItem'>
-                <label htmlFor={"interactions_across_regions"+track.id}>Interactions across regions:</label>
+                <label title="If true, will show interactions across regions (useful to show interactions across a breakpoint). If false, only show interactions within regions." htmlFor={"interactions_across_regions"+track.id}>Interactions across regions:</label>
                 <input type="checkbox" id={"interactions_across_regions"+track.id} checked={track.interactions_across_regions} onChange={() => set_value("interactions_across_regions",!track.interactions_across_regions)} />
             </div>
             {track.interactions_across_regions?(
                 <div className='formItem'>
-                <label htmlFor={"double_interactions_across_regions"+track.id}>Double across regions:</label>
+                <label title="If true, will double the interactions across regions, which can be useful if a translocation is present on only one of two alleles." htmlFor={"double_interactions_across_regions"+track.id}>Double across regions:</label>
                 <input type="checkbox" id={"double_interactions_across_regions"+track.id} checked={track.double_interactions_across_regions} onChange={() => set_value("double_interactions_across_regions",!track.double_interactions_across_regions)} />
             </div>
             ):""}
             <div className='formItem'>
-                <label htmlFor={"pixel_border"+track.id}>Pixel border:</label>
+                <label title="If true, will show a black border around each pixel." htmlFor={"pixel_border"+track.id}>Pixel border:</label>
                 <input type="checkbox" id={"pixel_border"+track.id} checked={track.pixel_border} onChange={() => set_value("pixel_border",!track.pixel_border)} />
             </div>
             <div className='formItem'>
-                <label htmlFor={"upside_down"+track.id}>Upside down:</label>
+                <label title="If true, will plot the track upside_down (distant interactions at the bottom)." htmlFor={"upside_down"+track.id}>Upside down:</label>
                 <input type="checkbox" id={"upside_down"+track.id} checked={track.upside_down} onChange={() => set_value("upside_down",!track.upside_down)} />
             </div>
         </div>
@@ -646,31 +646,31 @@ function SvTrack({track,set_value,openColorPanel, setFileDialogData,setFileDialo
     return (
         <>
         <div className="optionGroup">
-            <PathEntry id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass}  setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive} />
+            <PathEntry title="Path to the SV file, either in .vcf(.gz) format, or in .tsv with the following columns (optional columns in parentheses): chr1 pos1 chr2 pos2 (strand1) (strand2) (color)" id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass}  setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive} />
 
             <div className='formItem'>
-                <label htmlFor={"lw"+track.id}>Line width:</label>
+                <label title="Line width for the arcs showing SVs." htmlFor={"lw"+track.id}>Line width:</label>
                 <input id={"lw"+track.id} style={{width:"2em"}} value={track.lw}  onChange={(e) => set_value("lw",e.target.value)} ></input>
             </div>
 
             <div className='formItem'>
-                <label htmlFor={"color_del"+track.id}>DEL-like:</label>
+                <label title="Color for SVs whose orientation looks like a deletion (but this may not be a deletion in case of complex rearrangements)." htmlFor={"color_del"+track.id}>DEL-like:</label>
                 <ColorButton id={"color_del"+track.id} color={track.color_del} setColor={(c)=>set_value("color_del",c)} openColorPanel={openColorPanel}/>
             </div>
             <div className='formItem'>
-                <label htmlFor={"color_dup"+track.id}>DUP-like:</label>
+                <label title="Color for SVs whose orientation looks like a tandem duplication (but this may not be a duplication in case of complex rearrangements)." htmlFor={"color_dup"+track.id}>DUP-like:</label>
                 <ColorButton id={"color_dup"+track.id} color={track.color_dup} setColor={(c)=>set_value("color_dup",c)} openColorPanel={openColorPanel}/>
             </div>
             <div className='formItem'>
-                <label htmlFor={"color_h2h"+track.id}>H2H:</label>
+                <label title="Color for SVs whose orientation looks like a head-to-head inversion (but this may not be an inversion in case of complex rearrangements)." htmlFor={"color_h2h"+track.id}>H2H:</label>
                 <ColorButton id={"color_h2h"+track.id} color={track.color_h2h} setColor={(c)=>set_value("color_h2h",c)} openColorPanel={openColorPanel}/>
             </div>
             <div className='formItem'>
-                <label htmlFor={"color_t2t"+track.id}>T2T:</label>
+                <label title="Color for SVs whose orientation looks like a tail-to-tail inversion (but this may not be an inversion in case of complex rearrangements)." htmlFor={"color_t2t"+track.id}>T2T:</label>
                 <ColorButton id={"color_t2t"+track.id} color={track.color_t2t} setColor={(c)=>set_value("color_t2t",c)} openColorPanel={openColorPanel}/>
             </div>
             <div className='formItem'>
-                <label htmlFor={"color_trans"+track.id}>Translocation:</label>
+                <label title="Color for SVs connecting different chromosomes."  htmlFor={"color_trans"+track.id}>Translocation:</label>
                 <ColorButton id={"color_trans"+track.id} color={track.color_trans} setColor={(c)=>set_value("color_trans",c)} openColorPanel={openColorPanel}/>
             </div>
 
@@ -679,7 +679,7 @@ function SvTrack({track,set_value,openColorPanel, setFileDialogData,setFileDialo
         <div className="optionGroup">
 
             <div className='formItem'>
-                <label htmlFor={"min_sv_height"+track.id}>Min SV height:</label>
+                <label title="For circular layout: minimum height of the SV, so that even short SVs are visible." htmlFor={"min_sv_height"+track.id}>Min SV height:</label>
                 <input id={"min_sv_height"+track.id} style={{width:"2em"}} value={track.min_sv_height}  onChange={(e) => set_value("min_sv_height",e.target.value)} ></input>
             </div>
 
@@ -697,7 +697,7 @@ function CopynumberTrack({track,set_value,openColorPanel, setFileDialogData,setF
         <>
         <div className="optionGroup">
             <div className='formItem'>
-                <label htmlFor={"input_type"+track.id}>Input type:</label>
+                <label title="Type of input, depending on the tool that was used to get the CNA calls (it is also possible to use a different tool and convert to one of these formats)." htmlFor={"input_type"+track.id}>Input type:</label>
                 <select id={"input_type"+track.id} value={track.input_type} onChange={(e) =>{set_value("input_type",e.target.value)}}> 
                             <option className="dropDownOption" key="freec" value="freec">freec</option>
                             <option className="dropDownOption" key="purple" value="purple">purple</option>
@@ -723,21 +723,21 @@ function CopynumberTrack({track,set_value,openColorPanel, setFileDialogData,setF
 
         <div className="optionGroup">
             <div className='formItem'>
-                <label htmlFor={"ploidy"+track.id}>Ploidy:</label>
+                <label title="Ploidy of the sample (only for freec input)." htmlFor={"ploidy"+track.id}>Ploidy:</label>
                 <input id={"ploidy"+track.id} style={{width:"2em"}} value={track.ploidy}  onChange={(e) => set_value("ploidy",e.target.value)}/>
             </div>
 
             <div className='formItem'>
-                <label htmlFor={"min_cn"+track.id}>Min CN:</label>
+                <label title="Minimum copy number to show." htmlFor={"min_cn"+track.id}>Min CN:</label>
                 <input id={"min_cn"+track.id} style={{width:"2em"}} value={track.min_cn}  onChange={(e) => set_value("min_cn",e.target.value)}/>
             </div>
 
             <div className='formItem'>
-                <label htmlFor={"max_cn"+track.id}>Max CN:</label>
+                <label title="Maximum copy number to show." htmlFor={"max_cn"+track.id}>Max CN:</label>
                 <input id={"max_cn"+track.id} style={{width:"2em"}} value={track.max_cn}  onChange={(e) => set_value("max_cn",e.target.value)}/>
             </div>
             <div className='formItem'>
-                <label htmlFor={"genes"+track.id}>Genes:</label>
+                <label title="Comma-separated list of gene names to highlight." htmlFor={"genes"+track.id}>Genes:</label>
                 <input id={"genes"+track.id} style={{width:"7em"}} value={track.genes}  onChange={(e) => set_value("genes",e.target.value)} />
             </div>
 
@@ -745,25 +745,25 @@ function CopynumberTrack({track,set_value,openColorPanel, setFileDialogData,setF
 
         <div className="optionGroup">
             <div className='formItem'>
-                <label htmlFor={"marker_size"+track.id}>Marker size:</label>
+                <label title="Size of the markers indicating the copy number at each position." htmlFor={"marker_size"+track.id}>Marker size:</label>
                 <input id={"marker_size"+track.id} style={{width:"2em"}} value={track.marker_size}  onChange={(e) => set_value("marker_size",e.target.value)}/>
             </div>
             {/* Colors */}
             <div className='formItem'>
-                <label htmlFor={"color_normal"+track.id}>Normal:</label>
+                <label title="Color for positions without CNAs." htmlFor={"color_normal"+track.id}>Normal:</label>
                 <ColorButton id={"color_normal"+track.id} color={track.color_normal} setColor={(c)=>set_value("color_normal",c)} openColorPanel={openColorPanel}/>
             </div>
             <div className='formItem'>
-                <label htmlFor={"color_loss"+track.id}>Loss:</label>
+                 <label title="Color for positions with deletions." htmlFor={"color_loss"+track.id}>Loss:</label>
                 <ColorButton id={"color_loss"+track.id} color={track.color_loss} setColor={(c)=>set_value("color_loss",c)} openColorPanel={openColorPanel}/>
             </div>
             <div className='formItem'>
-                <label htmlFor={"color_gain"+track.id}>Gain:</label>
+                <label title="Color for positions with gains" htmlFor={"color_gain"+track.id}>Gain:</label>
                 <ColorButton id={"color_gain"+track.id} color={track.color_gain} setColor={(c)=>set_value("color_gain",c)} openColorPanel={openColorPanel}/>
             </div>
             {(track.input_type=="purple")?(
             <div className='formItem'>
-                <label htmlFor={"color_cnloh"+track.id}>CNLOH:</label>
+                <label title="Color for positions with copy-neutral loss of heterozygosity." htmlFor={"color_cnloh"+track.id}>CNLOH:</label>
                 <ColorButton id={"color_cnloh"+track.id} color={track.color_cnloh} setColor={(c)=>set_value("color_cnloh",c)} openColorPanel={openColorPanel}/>
             </div>):""}
         </div>
@@ -772,21 +772,21 @@ function CopynumberTrack({track,set_value,openColorPanel, setFileDialogData,setF
 
             {/* Grid */}
             <div className='formItem'>
-                <label htmlFor={"grid"+track.id}>Grid:</label>
+                <label title="Whether or not to display a grid with horizontal and vertical lines." htmlFor={"grid"+track.id}>Grid:</label>
                 <input type="checkbox" id={"grid"+track.id} checked={track.grid} onChange={() => set_value("grid",!track.grid)} ></input>
             </div>
             {track.grid? (
                 <>
                 <div className='formItem'>
-                    <label htmlFor={"grid_major"+track.id}>Grid major:</label>
+                    <label title="Whether or not to show vertical lines for the major ticks." htmlFor={"grid_major"+track.id}>Grid major:</label>
                     <input type="checkbox" id={"grid_major"+track.id} checked={track.grid_major} onChange={() => set_value("grid_major",!track.grid_major)} ></input>
                 </div>
                 <div className='formItem'>
-                    <label htmlFor={"grid_minor"+track.id}>Grid minor:</label>
+                    <label title="Whether or not to show vertical lines for the minor ticks." htmlFor={"grid_minor"+track.id}>Grid minor:</label>
                     <input type="checkbox" id={"grid_minor"+track.id} checked={track.grid_minor} onChange={() => set_value("grid_minor",!track.grid_minor)} ></input>
                 </div>
                 <div className='formItem'>
-                    <label htmlFor={"grid_cn"+track.id}>Grid CN:</label>
+                    <label title="Whether or not to show horizontal lines showing the copy numbers." htmlFor={"grid_cn"+track.id}>Grid CN:</label>
                     <input type="checkbox" id={"grid_cn"+track.id} checked={track.grid_cn} onChange={() => set_value("grid_cn",!track.grid_cn)} ></input>
                 </div>
             </>
@@ -804,8 +804,8 @@ function AseTrack({track,set_value,openColorPanel, setFileDialogData,setFileDial
     return (
         <>
             <div className="optionGroup">
-                <PathEntry id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass}  setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive}/>
-                <PathEntry id={"vcf_DNA"+track.id} label="VCF DNA:" value={track.vcf_DNA} set_value={(val) => set_value("vcf_DNA",val)} setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive}/>
+                <PathEntry title="Path to a file generated by fast_ase or GATK ASEReadCounter, containing allelic read counts in RNA-seq data." id={"file"+track.id} label="File:" value={track.file} set_value={(val) => set_value("file",val)} className={fileClass}  setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive}/>
+                <PathEntry title="Path to a vcf file containing allelic read counts in DNA-seq data (not required if the data was generated with fast_ase)." id={"vcf_DNA"+track.id} label="VCF DNA:" value={track.vcf_DNA} set_value={(val) => set_value("vcf_DNA",val)} setFileDialogData={setFileDialogData} setFileDialogActive={setFileDialogActive}/>
                 <div className='formItem' >
                     <label htmlFor={"color1"+track.id}>Color 1: </label>
                     <ColorButton id={"color1"+track.id} color={track.color1} setColor={(c)=>set_value("color1",c)} openColorPanel={openColorPanel}></ColorButton>
@@ -817,23 +817,23 @@ function AseTrack({track,set_value,openColorPanel, setFileDialogData,setFileDial
             </div>
             <div className="optionGroup">
                 <div className='formItem'>
-                    <label htmlFor={"min_depth"+track.id}>Min depth:</label>
+                    <label title="Minimum coverage in the RNA-seq data for a variant to be shown." htmlFor={"min_depth"+track.id}>Min depth:</label>
                     <input id={"min_depth"+track.id} style={{width:"3em"}} value={track.min_depth} onChange={(e) => set_value("min_depth",e.target.value)} ></input>
                 </div>
                 <div className='formItem'>
-                    <label htmlFor={"max_bar_width"+track.id}>Max bar width:</label>
+                    <label title="Maximum with of bars in mm (might actually be smaller in case many variants are present)." htmlFor={"max_bar_width"+track.id}>Max bar width:</label>
                     <input id={"max_bar_width"+track.id} style={{width:"3em"}} value={track.max_bar_width} onChange={(e) => set_value("max_bar_width",e.target.value)} ></input>
                 </div>
                 <div className='formItem'>
-                    <label htmlFor={"lw"+track.id}>lw:</label>
+                    <label title="Width for the line mapping each variant to its position." htmlFor={"lw"+track.id}>lw:</label>
                     <input id={"lw"+track.id} style={{width:"3em"}} value={track.lw} onChange={(e) => set_value("lw",e.target.value)} ></input>
                 </div>
                 <div className='formItem'>
-                    <label htmlFor={"only_exonic"+track.id}>Only exonic:</label>
+                    <label title="Whether to only show variants located in exons." htmlFor={"only_exonic"+track.id}>Only exonic:</label>
                     <input type="checkbox" id={"only_exonic"+track.id} checked={track.only_exonic} onChange={() => set_value("only_exonic",!track.only_exonic)} />
                 </div>
                 <div className='formItem'>
-                    <label htmlFor={"grid"+track.id}>Grid:</label>
+                    <label title="Whether to show horizontal lines for VAF of 25%, 50% and 75%." htmlFor={"grid"+track.id}>Grid:</label>
                     <input type="checkbox" id={"grid"+track.id} checked={track.grid} onChange={() => set_value("grid",!track.grid)} />
                 </div>
 
@@ -985,10 +985,10 @@ function select_file(set_value,initial_value,setFileDialogData,setFileDialogActi
         }
         });
 }
-export function PathEntry({id,label,value,set_value,className="",setFileDialogData,setFileDialogActive}){
+export function PathEntry({id,title="",label,value,set_value,className="",setFileDialogData,setFileDialogActive}){
     return(
         <div className='formItem '>
-            <label htmlFor={id}>{label}</label>
+            <label title={title} htmlFor={id}>{label}</label>
             <input id={id} value={value} className={className} onChange={(e)=>set_value(e.target.value) } style={{marginLeft:"2mm", marginRight:"1mm"}}></input>
             <button name="file" onClick={()=>select_file(set_value,value,setFileDialogData,setFileDialogActive)} className="buttonImage">
             <svg width="4.6mm" height="4.5mm" version="1.1" viewBox="0 0 576 512" xmlns="http://www.w3.org/2000/svg">