What is the use of this Built hint not documented in Developer guide?

[DurankGts]

how can I set full screen in android or ios . For example in android how can I hide the system tool while my app is open and dragging in bottom or left side the system tool butoms (Back, home, recentApps) appear like other apps?

[shai-almog]

That is a capability designed for gaming not for regular apps. By default apps stretch the entire screen on both iOS and Android.