Making a Splash Screen (25/7/2015)

splash_screen

Assuming you have a theme called AppTheme, your launcher theme would be:

<style name="AppTheme.Launcher">
  <item name="android:windowBackground">@drawable/launch_screen</item>
  <item name="colorPrimaryDark"></item>
</style>

But drawable/launch_screen can’t be just a simple image, unfortunately - it’ll end up stretched to fill the entire screen. 
Instead, you can use an XML file such as:

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" 
  android:opacity="opaque">
  <!-- The background color, preferably the same as your normal theme -->
  <item android:drawable="@android:color/white"/>
  <!-- Your product logo - 144dp color version of your app icon -->
  <item>
    <bitmap
      android:src="@drawable/product_logo_144dp"
      android:gravity="center"/>
  </item>
</layer-list>

Apply your theme to your activity in your AndroidManifest.xml using android:theme="@style/AppTheme.Launcher".

The easiest way to transition back to your normal theme is to call setTheme(R.style.AppTheme) before super.onCreate():

public class MyMainActivity extends AppCompatActivity {
 @Override
  protected void onCreate(Bundle savedInstanceState) {
    // Make sure this is before calling super.onCreate and setContentView
    setTheme(R.style.Theme_MyApp);
    super.onCreate(savedInstanceState);
    // ...
  }
}

by Ian Lake - https://plus.google.com/+AndroidDevelopers/posts/Z1Wwainpjhd