wrote a detailed article on two interesting features of Android, Immersive mode and Navigation Bar Styling
Immersive (or Full Screen) Mode
on Android hides the navigation and status bars and lets your app capture all touch events on the screen. Using this technique, you can take over more of the screen with your application. There are several modes of Immersion and each one gives different benefits.
Coloring the Navigation Bar
Further, many NativeScript users have questioned how best to add color to the Navigation bar. Brad details how to accomplish this, complete with source code examples.