MainWindow.xaml

<Window x:Class="FloatingClock.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:FloatingClock"
        xmlns:properties="clr-namespace:FloatingClock.Properties"
        mc:Ignorable="d"
        Title="FloatingClock" Height="120" Width="120"
        WindowStyle="None"
        AllowsTransparency="True"
        Background="Transparent"
        ShowInTaskbar="False"
        Topmost="{Binding Source={x:Static properties:Settings.Default}, Path=AlwaysOnTop}"
        Top="{Binding Source={x:Static properties:Settings.Default}, Path=WindowTop, Mode=TwoWay}"
        Left="{Binding Source={x:Static properties:Settings.Default}, Path=WindowLeft, Mode=TwoWay}"
        MouseRightButtonDown="Handle_RightButtonDown"
        MouseLeftButtonDown="Handle_LeftButtonDown"
        ContentRendered="Handle_ContentRendered"
        Closing="Handle_Closing"
        >
    <Window.ContextMenu>
        <ContextMenu>
            <MenuItem Header="Always on Top" IsCheckable="True" IsChecked="{Binding Source={x:Static properties:Settings.Default}, Path=AlwaysOnTop}"/>
            <MenuItem Header="About" Click="Handle_About"/>
            <MenuItem Header="Exit" Click="Handle_Exit"/>
        </ContextMenu>
    </Window.ContextMenu>
    <local:Clock x:Name="Clock"/>
</Window>