Fullscreen/immersive mode

[daggerstab]

The app would benefit from adding, at least as an option, a fullscreen mode that hides the toolbar and the system bar. On phones, this would add about 2 centimeters of length to the rulers.

See the Android documentation about immersive mode: https://developer.android.com/training/system-ui/immersive.html

[alekksander]

yes please