The application is made of 5 simple activities, each one characterized by a particular background.
To be not redundant, we show just one of the xml files related to the layouts of the activities, for example the one of activity #2, SecondActivity.java:
The layout is defined in second.xml:
The typologies of gradient background are defined in drawable folder, and are the following ones:
You can download the complete example from our repository: Download GradientBackground.zip
The final result is the following: