Android Permissions

All you ever wanted to know about Android permissions

android.permission.SYSTEM_ALERT_WINDOW

draw over other apps
Allows the app to draw on top of other applications or parts of the user interface. They may interfere with your use of the interface in any application, or change what you think you are seeing in other applications.

Belongs to:

android.permission-group.DISPLAY

Other Application UI
Effect the UI of other applications.