Using other Android apps

Question

There is an interesting app called Twilight that seems to simply paint all apps with a reddish filter to remove blue light at night (presumably to help sleep).

I am interested in doing something similar, but not necessary for sleep. I would like to draw a text or watermark on top of everything on the phone. How can I do this (draw an action or something like this on everything) in Android?

Answer 1

You should look at the Android System Overlay, which pretty much captures the look at the root on the Android Window Manager .

: ( )

"android.permission.SYSTEM_ALERT_WINDOW".

: http://developer.android.com/reference/android/Manifest.permission.html#SYSTEM_ALERT_WINDOW

Windows