Hide the title bar & be full screen

Add a style into your styles.xml:

 
<style name="MyNoTitleAndFullscreenTheme" parent="AppBaseTheme">
  <!-- Hide the status bar -->
  <item name="android:windowFullscreen">true</item>
  <!-- Hide the title bar -->
  <item name="android:windowNoTitle">true</item>
</style>

And apply it in an activity (in your AndroidManifest.xml:

 
xxxxxxxxxx
<activity 
        android:name="the.activity.name"
        android:theme="@style/MyNoTitleAndFullscreenTheme">
</activity>