diff --git a/app/build.gradle b/app/build.gradle
index 0d91e5c..b7da2eb 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -1,15 +1,15 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 23
-    buildToolsVersion "24.0.0 rc1"
+    compileSdkVersion 24
+    buildToolsVersion "24.0.2"
 
     defaultConfig {
         applicationId "com.aspsine.fragmentnavigator.demo"
         minSdkVersion 11
-        targetSdkVersion 23
-        versionCode 2
-        versionName "2.0"
+        targetSdkVersion 24
+        versionCode 3
+        versionName "3.0"
     }
     buildTypes {
         release {
@@ -17,12 +17,16 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+    repositories {
+        maven { url "https://jitpack.io" }
+    }
 }
 
 dependencies {
     compile fileTree(include: ['*.jar'], dir: 'libs')
-    testCompile 'junit:junit:4.12'
     compile project(':library')
-    compile 'com.android.support:appcompat-v7:23.3.0'
-    compile 'com.android.support:support-v4:23.3.0'
+//    compile 'com.github.Aspsine:FragmentNavigator:1.0.2'
+    compile 'com.android.support:appcompat-v7:24.2.0'
+    compile 'com.android.support:design:24.2.0'
+    testCompile 'junit:junit:4.12'
 }
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index c3e02d0..45d9136 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -2,6 +2,11 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.aspsine.fragmentnavigator.demo">
 
+    <!-- To auto-complete the email text field in the login form with the user's emails -->
+    <uses-permission android:name="android.permission.GET_ACCOUNTS" />
+    <uses-permission android:name="android.permission.READ_PROFILE" />
+    <uses-permission android:name="android.permission.READ_CONTACTS" />
+
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
@@ -9,7 +14,7 @@
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
         <activity
-            android:name=".MainActivity"
+            android:name=".ui.activity.MainActivity"
             android:launchMode="singleTask">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
@@ -17,7 +22,12 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-        <activity android:name=".ExceptionActivity" />
+
+        <activity android:name=".ui.activity.ExceptionActivity" />
+
+        <activity
+            android:name=".ui.activity.LoginActivity"
+            android:label="@string/title_activity_login"/>
     </application>
 
 </manifest>
\ No newline at end of file
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/Action.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/Action.java
new file mode 100644
index 0000000..9324a3f
--- /dev/null
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/Action.java
@@ -0,0 +1,10 @@
+package com.aspsine.fragmentnavigator.demo;
+
+/**
+ * Created by aspsine on 16/9/3.
+ */
+
+public class Action {
+    public static final String LOGIN = Action.class.getName() + ".LOGIN";
+    public static final String LOGOUT = Action.class.getName() + ".LOGOUT";
+}
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/MainActivity.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/MainActivity.java
deleted file mode 100644
index 7272098..0000000
--- a/app/src/main/java/com/aspsine/fragmentnavigator/demo/MainActivity.java
+++ /dev/null
@@ -1,66 +0,0 @@
-package com.aspsine.fragmentnavigator.demo;
-
-import android.content.Intent;
-import android.os.Bundle;
-import android.support.v7.app.AppCompatActivity;
-import android.view.Menu;
-import android.view.MenuItem;
-import android.view.View;
-
-import com.aspsine.fragmentnavigator.FragmentNavigator;
-
-public class MainActivity extends AppCompatActivity implements BottomNavigatorView.OnBottomNavigatorViewItemClickListener {
-
-    private static final int DEFAULT_POSITION = 0;
-
-    private FragmentNavigator mNavigator;
-
-    private BottomNavigatorView bottomNavigatorView;
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_main);
-
-        mNavigator = new FragmentNavigator(getSupportFragmentManager(), new FragmentAdapter(), R.id.container);
-        mNavigator.setDefaultPosition(DEFAULT_POSITION);
-        mNavigator.onCreate(savedInstanceState);
-
-        bottomNavigatorView = (BottomNavigatorView) findViewById(R.id.bottomNavigatorView);
-        if (bottomNavigatorView != null) {
-            bottomNavigatorView.setOnBottomNavigatorViewItemClickListener(this);
-        }
-
-        setCurrentTab(mNavigator.getCurrentPosition());
-    }
-
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        getMenuInflater().inflate(R.menu.menu_exception, menu);
-        return true;
-    }
-
-    @Override
-    protected void onSaveInstanceState(Bundle outState) {
-        super.onSaveInstanceState(outState);
-        mNavigator.onSaveInstanceState(outState);
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        if (item.getItemId() == R.id.action_exception) {
-            startActivity(new Intent(this, ExceptionActivity.class));
-        }
-        return super.onOptionsItemSelected(item);
-    }
-
-    @Override
-    public void onBottomNavigatorViewItemClick(int position, View view) {
-        setCurrentTab(position);
-    }
-
-    private void setCurrentTab(int position) {
-        mNavigator.showFragment(position);
-        bottomNavigatorView.select(position);
-    }
-}
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/broadcast/BroadcastManager.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/broadcast/BroadcastManager.java
new file mode 100644
index 0000000..66e5583
--- /dev/null
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/broadcast/BroadcastManager.java
@@ -0,0 +1,40 @@
+package com.aspsine.fragmentnavigator.demo.broadcast;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.support.v4.content.LocalBroadcastManager;
+
+import com.aspsine.fragmentnavigator.demo.Action;
+
+/**
+ * Created by aspsine on 16/9/3.
+ */
+
+public class BroadcastManager {
+
+    public static void register(Context context, BroadcastReceiver receiver, String... actions){
+        IntentFilter filter = new IntentFilter();
+        for (String action: actions){
+            filter.addAction(action);
+        }
+        LocalBroadcastManager.getInstance(context).registerReceiver(receiver, filter);
+    }
+
+    public static void unregister(Context context, BroadcastReceiver receiver){
+        LocalBroadcastManager.getInstance(context).unregisterReceiver(receiver);
+    }
+
+    public static void sendLoginBroadcast(Context context, int position){
+        Intent intent = new Intent(Action.LOGIN);
+        intent.putExtra("EXTRA_POSITION", position);
+        LocalBroadcastManager.getInstance(context).sendBroadcast(intent);
+    }
+
+    public static void sendLogoutBroadcast(Context context, int position){
+        Intent intent = new Intent(Action.LOGOUT);
+        intent.putExtra("EXTRA_POSITION", position);
+        LocalBroadcastManager.getInstance(context).sendBroadcast(intent);
+    }
+}
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/ExceptionActivity.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/activity/ExceptionActivity.java
similarity index 87%
rename from app/src/main/java/com/aspsine/fragmentnavigator/demo/ExceptionActivity.java
rename to app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/activity/ExceptionActivity.java
index 559eaea..3797d64 100644
--- a/app/src/main/java/com/aspsine/fragmentnavigator/demo/ExceptionActivity.java
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/activity/ExceptionActivity.java
@@ -1,10 +1,12 @@
-package com.aspsine.fragmentnavigator.demo;
+package com.aspsine.fragmentnavigator.demo.ui.activity;
 
 import android.os.Bundle;
 import android.support.v7.app.AppCompatActivity;
 import android.view.View;
 import android.widget.Button;
 
+import com.aspsine.fragmentnavigator.demo.R;
+
 public class ExceptionActivity extends AppCompatActivity {
 
     @Override
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/activity/LoginActivity.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/activity/LoginActivity.java
new file mode 100644
index 0000000..977c808
--- /dev/null
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/activity/LoginActivity.java
@@ -0,0 +1,67 @@
+package com.aspsine.fragmentnavigator.demo.ui.activity;
+
+import android.os.Bundle;
+import android.support.v7.app.AppCompatActivity;
+import android.text.TextUtils;
+import android.view.View;
+import android.widget.Button;
+import android.widget.EditText;
+
+import com.aspsine.fragmentnavigator.demo.R;
+import com.aspsine.fragmentnavigator.demo.broadcast.BroadcastManager;
+import com.aspsine.fragmentnavigator.demo.utils.SharedPrefUtils;
+
+public class LoginActivity extends AppCompatActivity implements View.OnClickListener{
+
+    private EditText etEmail;
+    private EditText etPassword;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_login);
+        etEmail = (EditText) findViewById(R.id.et_email);
+        etPassword  = (EditText)findViewById(R.id.et_password);
+        Button button = (Button) findViewById(R.id.login_in_button);
+        button.setOnClickListener(this);
+    }
+
+    @Override
+    public void onClick(View v) {
+        if (v.getId() == R.id.login_in_button){
+            tryLogin();
+        }
+    }
+
+    void tryLogin(){
+        String email = String.valueOf(etEmail.getText()).trim();
+        String password = String.valueOf(etPassword.getText()).trim();
+
+        if(check(email, password)){
+            markUserLogin();
+            notifyUserLogin();
+            finish();
+        }
+    }
+
+    boolean check(String email, String password){
+        if (TextUtils.isEmpty(email)){
+            etEmail.setError(getString(R.string.error_invalid_email));
+            return false;
+        }
+        if (TextUtils.isEmpty(password)){
+            etPassword.setError(getString(R.string.error_invalid_password));
+            return false;
+        }
+        return true;
+    }
+
+    private void markUserLogin(){
+        SharedPrefUtils.login(this);
+    }
+
+    private void notifyUserLogin(){
+        BroadcastManager.sendLoginBroadcast(this, 1);
+    }
+}
+
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/activity/MainActivity.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/activity/MainActivity.java
new file mode 100644
index 0000000..3240a2f
--- /dev/null
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/activity/MainActivity.java
@@ -0,0 +1,153 @@
+package com.aspsine.fragmentnavigator.demo.ui.activity;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+import android.support.v7.app.AppCompatActivity;
+import android.text.TextUtils;
+import android.view.Menu;
+import android.view.MenuItem;
+import android.view.View;
+
+import com.aspsine.fragmentnavigator.FragmentNavigator;
+import com.aspsine.fragmentnavigator.demo.Action;
+import com.aspsine.fragmentnavigator.demo.R;
+import com.aspsine.fragmentnavigator.demo.broadcast.BroadcastManager;
+import com.aspsine.fragmentnavigator.demo.ui.adapter.FragmentAdapter;
+import com.aspsine.fragmentnavigator.demo.ui.widget.BottomNavigatorView;
+import com.aspsine.fragmentnavigator.demo.utils.SharedPrefUtils;
+
+public class MainActivity extends AppCompatActivity implements BottomNavigatorView.OnBottomNavigatorViewItemClickListener {
+
+    private static final int DEFAULT_POSITION = 0;
+
+    private FragmentNavigator mNavigator;
+
+    private BottomNavigatorView bottomNavigatorView;
+
+    private MenuItem mLoginMenu;
+
+    private MenuItem mLogoutMenu;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_main);
+
+        mNavigator = new FragmentNavigator(getSupportFragmentManager(), new FragmentAdapter(), R.id.container);
+        mNavigator.setDefaultPosition(DEFAULT_POSITION);
+        mNavigator.onCreate(savedInstanceState);
+
+        bottomNavigatorView = (BottomNavigatorView) findViewById(R.id.bottomNavigatorView);
+        if (bottomNavigatorView != null) {
+            bottomNavigatorView.setOnBottomNavigatorViewItemClickListener(this);
+        }
+
+        setCurrentTab(mNavigator.getCurrentPosition());
+
+        BroadcastManager.register(this, mLoginStatusChangeReceiver, Action.LOGIN, Action.LOGOUT);
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        getMenuInflater().inflate(R.menu.menu_main, menu);
+        mLoginMenu = menu.findItem(R.id.action_login);
+        mLogoutMenu = menu.findItem(R.id.action_logout);
+        toggleMenu(SharedPrefUtils.isLogin(this));
+        return true;
+    }
+
+    @Override
+    protected void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+        mNavigator.onSaveInstanceState(outState);
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        int id = item.getItemId();
+        switch (id) {
+            case R.id.action_exception:
+                startActivity(new Intent(this, ExceptionActivity.class));
+                return true;
+            case R.id.action_login:
+                startActivity(new Intent(this, LoginActivity.class));
+                return true;
+            case R.id.action_logout:
+                logout();
+                return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
+    @Override
+    protected void onDestroy() {
+        BroadcastManager.unregister(this, mLoginStatusChangeReceiver);
+        super.onDestroy();
+    }
+
+    @Override
+    public void onBottomNavigatorViewItemClick(int position, View view) {
+        setCurrentTab(position);
+    }
+
+    private void logout(){
+        SharedPrefUtils.logout(this);
+        BroadcastManager.sendLogoutBroadcast(this, 1);
+    }
+
+    private void onUserLogin(int position) {
+        if (position == -1) {
+            resetAllTabsAndShow(mNavigator.getCurrentPosition());
+        } else {
+            resetAllTabsAndShow(position);
+        }
+        toggleMenu(true);
+    }
+
+    private void onUserLogout(int position) {
+        if (position == -1) {
+            resetAllTabsAndShow(mNavigator.getCurrentPosition());
+        } else {
+            resetAllTabsAndShow(position);
+        }
+        toggleMenu(false);
+    }
+
+    private void setCurrentTab(int position) {
+        mNavigator.showFragment(position);
+        bottomNavigatorView.select(position);
+    }
+
+    private void resetAllTabsAndShow(int position){
+        mNavigator.resetFragments(position, true);
+        bottomNavigatorView.select(position);
+    }
+
+    private void toggleMenu(boolean login) {
+        if (login) {
+            mLoginMenu.setVisible(false);
+            mLogoutMenu.setVisible(true);
+        } else {
+            mLoginMenu.setVisible(true);
+            mLogoutMenu.setVisible(false);
+        }
+    }
+
+    private BroadcastReceiver mLoginStatusChangeReceiver = new BroadcastReceiver() {
+
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            String action = intent.getAction();
+            if (!TextUtils.isEmpty(action)) {
+                int position = intent.getIntExtra("EXTRA_POSITION", -1);
+                if (action.equals(Action.LOGIN)) {
+                    onUserLogin(position);
+                } else if (action.equals(Action.LOGOUT)) {
+                    onUserLogout(position);
+                }
+            }
+        }
+    };
+}
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/ChildFragmentAdapter.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/adapter/ChildFragmentAdapter.java
similarity index 83%
rename from app/src/main/java/com/aspsine/fragmentnavigator/demo/ChildFragmentAdapter.java
rename to app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/adapter/ChildFragmentAdapter.java
index b1b5933..8cd0a0c 100644
--- a/app/src/main/java/com/aspsine/fragmentnavigator/demo/ChildFragmentAdapter.java
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/adapter/ChildFragmentAdapter.java
@@ -1,8 +1,9 @@
-package com.aspsine.fragmentnavigator.demo;
+package com.aspsine.fragmentnavigator.demo.ui.adapter;
 
 import android.support.v4.app.Fragment;
 
 import com.aspsine.fragmentnavigator.FragmentNavigatorAdapter;
+import com.aspsine.fragmentnavigator.demo.ui.fragment.MainFragment;
 
 /**
  * Created by aspsine on 16/4/3.
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/FragmentAdapter.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/adapter/FragmentAdapter.java
similarity index 80%
rename from app/src/main/java/com/aspsine/fragmentnavigator/demo/FragmentAdapter.java
rename to app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/adapter/FragmentAdapter.java
index e1ff4f4..0bb3635 100644
--- a/app/src/main/java/com/aspsine/fragmentnavigator/demo/FragmentAdapter.java
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/adapter/FragmentAdapter.java
@@ -1,8 +1,10 @@
-package com.aspsine.fragmentnavigator.demo;
+package com.aspsine.fragmentnavigator.demo.ui.adapter;
 
 import android.support.v4.app.Fragment;
 
 import com.aspsine.fragmentnavigator.FragmentNavigatorAdapter;
+import com.aspsine.fragmentnavigator.demo.ui.fragment.ContactsFragment;
+import com.aspsine.fragmentnavigator.demo.ui.fragment.MainFragment;
 
 /**
  * Created by aspsine on 16/3/31.
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/ContactsFragment.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/fragment/ContactsFragment.java
similarity index 90%
rename from app/src/main/java/com/aspsine/fragmentnavigator/demo/ContactsFragment.java
rename to app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/fragment/ContactsFragment.java
index 57bcd17..47a49ed 100644
--- a/app/src/main/java/com/aspsine/fragmentnavigator/demo/ContactsFragment.java
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/fragment/ContactsFragment.java
@@ -1,4 +1,4 @@
-package com.aspsine.fragmentnavigator.demo;
+package com.aspsine.fragmentnavigator.demo.ui.fragment;
 
 
 import android.os.Bundle;
@@ -10,6 +10,9 @@
 import android.view.ViewGroup;
 
 import com.aspsine.fragmentnavigator.FragmentNavigator;
+import com.aspsine.fragmentnavigator.demo.R;
+import com.aspsine.fragmentnavigator.demo.ui.widget.TabLayout;
+import com.aspsine.fragmentnavigator.demo.ui.adapter.ChildFragmentAdapter;
 
 
 /**
@@ -57,7 +60,6 @@ public void onTabItemClick(int position, View view) {
     public void onActivityCreated(@Nullable Bundle savedInstanceState) {
         super.onActivityCreated(savedInstanceState);
         setCurrentTab(mNavigator.getCurrentPosition());
-        Log.i(TAG, "onActivityCreated");
     }
 
     @Override
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/MainFragment.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/fragment/MainFragment.java
similarity index 83%
rename from app/src/main/java/com/aspsine/fragmentnavigator/demo/MainFragment.java
rename to app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/fragment/MainFragment.java
index 4c8db6b..58c780b 100644
--- a/app/src/main/java/com/aspsine/fragmentnavigator/demo/MainFragment.java
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/fragment/MainFragment.java
@@ -1,4 +1,4 @@
-package com.aspsine.fragmentnavigator.demo;
+package com.aspsine.fragmentnavigator.demo.ui.fragment;
 
 
 import android.os.Bundle;
@@ -12,6 +12,9 @@
 import android.widget.ProgressBar;
 import android.widget.TextView;
 
+import com.aspsine.fragmentnavigator.demo.R;
+import com.aspsine.fragmentnavigator.demo.utils.SharedPrefUtils;
+
 import java.lang.ref.WeakReference;
 
 /**
@@ -70,7 +73,18 @@ public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
     @Override
     public void onActivityCreated(@Nullable Bundle savedInstanceState) {
         super.onActivityCreated(savedInstanceState);
-        loadData();
+        if (savedInstanceState == null) {
+            loadData();
+        } else {
+            mText = savedInstanceState.getString(EXTRA_TEXT);
+            bindData();
+        }
+    }
+
+    @Override
+    public void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+        outState.putString(EXTRA_TEXT, mText);
     }
 
     @Override
@@ -86,7 +100,8 @@ private void showProgressBar(boolean show) {
     }
 
     private void bindData() {
-        tvText.setText(mText);
+        boolean isLogin = SharedPrefUtils.isLogin(getActivity());
+        tvText.setText(mText + "\n" + "Login:" + isLogin);
     }
 
     /**
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/BottomNavigatorView.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/widget/BottomNavigatorView.java
similarity index 96%
rename from app/src/main/java/com/aspsine/fragmentnavigator/demo/BottomNavigatorView.java
rename to app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/widget/BottomNavigatorView.java
index 35220ba..3189e23 100644
--- a/app/src/main/java/com/aspsine/fragmentnavigator/demo/BottomNavigatorView.java
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/widget/BottomNavigatorView.java
@@ -1,4 +1,4 @@
-package com.aspsine.fragmentnavigator.demo;
+package com.aspsine.fragmentnavigator.demo.ui.widget;
 
 import android.content.Context;
 import android.graphics.PorterDuff;
@@ -9,6 +9,8 @@
 import android.view.ViewGroup;
 import android.widget.ImageView;
 
+import com.aspsine.fragmentnavigator.demo.R;
+
 /**
  * Created by aspsine on 16/3/31.
  */
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/TabLayout.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/widget/TabLayout.java
similarity index 95%
rename from app/src/main/java/com/aspsine/fragmentnavigator/demo/TabLayout.java
rename to app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/widget/TabLayout.java
index e6488e4..aea266a 100644
--- a/app/src/main/java/com/aspsine/fragmentnavigator/demo/TabLayout.java
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/ui/widget/TabLayout.java
@@ -1,4 +1,4 @@
-package com.aspsine.fragmentnavigator.demo;
+package com.aspsine.fragmentnavigator.demo.ui.widget;
 
 import android.content.Context;
 import android.util.AttributeSet;
@@ -6,6 +6,8 @@
 import android.view.ViewGroup;
 import android.widget.LinearLayout;
 
+import com.aspsine.fragmentnavigator.demo.R;
+
 /**
  * Created by aspsine on 16/4/1.
  */
diff --git a/app/src/main/java/com/aspsine/fragmentnavigator/demo/utils/SharedPrefUtils.java b/app/src/main/java/com/aspsine/fragmentnavigator/demo/utils/SharedPrefUtils.java
new file mode 100644
index 0000000..0b1ff69
--- /dev/null
+++ b/app/src/main/java/com/aspsine/fragmentnavigator/demo/utils/SharedPrefUtils.java
@@ -0,0 +1,32 @@
+package com.aspsine.fragmentnavigator.demo.utils;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+
+/**
+ * Created by aspsine on 16/9/2.
+ */
+
+public class SharedPrefUtils {
+
+    private static final String SHARED_PREF_LOGIN = "login";
+
+    public static void login(Context context){
+        SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREF_LOGIN, Context.MODE_PRIVATE);
+        SharedPreferences.Editor editor = sharedPreferences.edit();
+        editor.putBoolean("login", true);
+        editor.commit();
+    }
+
+    public static void logout(Context context){
+        SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREF_LOGIN, Context.MODE_PRIVATE);
+        SharedPreferences.Editor editor = sharedPreferences.edit();
+        editor.putBoolean("login", false);
+        editor.commit();
+    }
+
+    public static boolean isLogin(Context context){
+        SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREF_LOGIN, Context.MODE_PRIVATE);
+        return sharedPreferences.getBoolean("login", false);
+    }
+}
diff --git a/app/src/main/res/layout/activity_exception.xml b/app/src/main/res/layout/activity_exception.xml
index 8356df9..1f2a152 100644
--- a/app/src/main/res/layout/activity_exception.xml
+++ b/app/src/main/res/layout/activity_exception.xml
@@ -8,7 +8,7 @@
     android:paddingRight="@dimen/activity_horizontal_margin"
     android:paddingTop="@dimen/activity_vertical_margin"
     android:orientation="vertical"
-    tools:context="com.aspsine.fragmentnavigator.demo.ExceptionActivity">
+    tools:context="com.aspsine.fragmentnavigator.demo.ui.activity.ExceptionActivity">
 
     <TextView
         android:layout_width="match_parent"
diff --git a/app/src/main/res/layout/activity_login.xml b/app/src/main/res/layout/activity_login.xml
new file mode 100644
index 0000000..177d6e9
--- /dev/null
+++ b/app/src/main/res/layout/activity_login.xml
@@ -0,0 +1,50 @@
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:gravity="center_horizontal"
+    android:orientation="vertical"
+    android:paddingBottom="@dimen/activity_vertical_margin"
+    android:paddingLeft="@dimen/activity_horizontal_margin"
+    android:paddingRight="@dimen/activity_horizontal_margin"
+    android:paddingTop="@dimen/activity_vertical_margin"
+    tools:context="com.aspsine.fragmentnavigator.demo.ui.activity.LoginActivity">
+
+    <ScrollView
+        android:id="@+id/login_form"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <LinearLayout
+            android:id="@+id/email_login_form"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="vertical">
+
+                <EditText
+                    android:id="@+id/et_email"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:hint="@string/prompt_email"
+                    android:maxLines="1"/>
+
+                <EditText
+                    android:id="@+id/et_password"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:hint="@string/prompt_password"
+                    android:inputType="textPassword"
+                    android:maxLines="1"/>
+
+            <Button
+                android:id="@+id/login_in_button"
+                style="?android:textAppearanceSmall"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="16dp"
+                android:text="@string/action_log_in"
+                android:textStyle="bold" />
+
+        </LinearLayout>
+    </ScrollView>
+</LinearLayout>
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index 474f4f1..e29100c 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -4,7 +4,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical"
-    tools:context=".MainActivity">
+    tools:context=".ui.activity.MainActivity">
 
     <FrameLayout
         android:id="@+id/container"
@@ -12,7 +12,7 @@
         android:layout_height="0dp"
         android:layout_weight="1" />
 
-    <com.aspsine.fragmentnavigator.demo.BottomNavigatorView
+    <com.aspsine.fragmentnavigator.demo.ui.widget.BottomNavigatorView
         android:id="@+id/bottomNavigatorView"
         android:layout_width="match_parent"
         android:layout_height="56dp"
diff --git a/app/src/main/res/layout/fragment_contacts.xml b/app/src/main/res/layout/fragment_contacts.xml
index 5a7c40b..6eecb1b 100644
--- a/app/src/main/res/layout/fragment_contacts.xml
+++ b/app/src/main/res/layout/fragment_contacts.xml
@@ -3,9 +3,9 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical"
-    tools:context=".ContactsFragment">
+    tools:context=".ui.fragment.ContactsFragment">
 
-    <com.aspsine.fragmentnavigator.demo.TabLayout
+    <com.aspsine.fragmentnavigator.demo.ui.widget.TabLayout
         android:id="@+id/tabLayout"
         android:layout_width="match_parent"
         android:background="@android:color/white"
diff --git a/app/src/main/res/layout/fragment_main.xml b/app/src/main/res/layout/fragment_main.xml
index e7f175c..0f4f447 100644
--- a/app/src/main/res/layout/fragment_main.xml
+++ b/app/src/main/res/layout/fragment_main.xml
@@ -2,14 +2,15 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context=".MainFragment">
+    tools:context=".ui.fragment.MainFragment">
 
     <TextView
         android:id="@+id/tvText"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_gravity="center"
-        android:textSize="80sp"
+        android:textSize="60sp"
+        android:gravity="center"
         tools:text="Text" />
 
     <ProgressBar
@@ -17,6 +18,7 @@
         style="?android:progressBarStyleLargeInverse"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
+        android:visibility="gone"
         android:layout_gravity="center" />
 
 </FrameLayout>
diff --git a/app/src/main/res/menu/menu_exception.xml b/app/src/main/res/menu/menu_main.xml
similarity index 50%
rename from app/src/main/res/menu/menu_exception.xml
rename to app/src/main/res/menu/menu_main.xml
index 873cc97..f39b03f 100644
--- a/app/src/main/res/menu/menu_exception.xml
+++ b/app/src/main/res/menu/menu_main.xml
@@ -1,9 +1,22 @@
 <?xml version="1.0" encoding="utf-8"?>
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto">
+
     <item
-        android:id="@+id/action_exception"
+        android:id="@+id/action_login"
         android:orderInCategory="100"
+        android:title="@string/action_log_in"
+        app:showAsAction="never" />
+
+    <item
+        android:id="@+id/action_exception"
+        android:orderInCategory="200"
         android:title="@string/action_exception"
         app:showAsAction="always" />
+
+    <item
+        android:id="@+id/action_logout"
+        android:orderInCategory="300"
+        android:title="@string/action_log_out"
+        app:showAsAction="never" />
 </menu>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index b3bfda8..f2fa542 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -5,4 +5,15 @@
     <string name="hello_blank_fragment">Hello blank fragment</string>
 
     <string name="action_exception">Exception</string>
+
+    <!-- Strings related to login -->
+    <string name="title_activity_login">Log in</string>
+    <string name="prompt_email">Email</string>
+    <string name="prompt_password">Password</string>
+    <string name="action_log_in">Log in</string>
+    <string name="action_log_out">Log out</string>
+    <string name="prompt_login_success">Welcome</string>
+    <string name="error_invalid_email">email is empty</string>
+    <string name="error_invalid_password">password is empty</string>
+
 </resources>
diff --git a/art/demo.apk b/art/demo.apk
index 6bb028e..77be24f 100644
Binary files a/art/demo.apk and b/art/demo.apk differ
diff --git a/build.gradle b/build.gradle
index c620d53..77ce66e 100644
--- a/build.gradle
+++ b/build.gradle
@@ -5,7 +5,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.1.0-rc1'
+        classpath 'com.android.tools.build:gradle:2.1.3'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 122a0dc..8ef0dfe 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Mon Dec 28 10:00:20 PST 2015
+#Fri Sep 02 21:25:05 CST 2016
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.10-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.14.1-all.zip
diff --git a/library/build.gradle b/library/build.gradle
index 663e55a..ce9adc3 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -1,12 +1,12 @@
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 23
-    buildToolsVersion "24.0.0 rc1"
+    compileSdkVersion 24
+    buildToolsVersion "24.0.2"
 
     defaultConfig {
         minSdkVersion 10
-        targetSdkVersion 23
+        targetSdkVersion 24
         versionCode 3
         versionName "1.0.2"
     }
@@ -21,5 +21,5 @@ android {
 dependencies {
     compile fileTree(include: ['*.jar'], dir: 'libs')
     testCompile 'junit:junit:4.12'
-    compile 'com.android.support:support-v4:23.3.0'
+    compile 'com.android.support:support-fragment:24.2.0'
 }