Allows an app to create windows using the type TYPE_APPLICATION_OVERLAY, shown on top of all other apps. Very few apps should use this permission; these windows are intended for system-level interaction with the user. Note: If the app targets API level 23 or higher, the app user must explicitly grant this permission to the app through a permission management screen. The app requests the user's approval by sending an intent with action ACTION_MANAGE_OVERLAY_PERMISSION. The app can check whether it has this authorization by calling android.provider.Settings#canDrawOverlays Settings.canDrawOverlays()