I had a problem the other day.. Android has a protection against malicious apps doing overlay (screen filters, buttons etc); when installing custom APK, you can't press Install
button. On my phone I had to install an app to list all apps having the overlay permission, specifically this:
Code: Select all
Advanced Permission Manager
After filtering which apps could do that, I was able to pinpoint the problem app and use Titanium Backup to freeze it (check if it is the guilty one).
I'd be happy if you could share what apps you've found out could do that for others to know.
In my case it was Lux Auto Brightness (1.75) [CM 12.1/Android 5.1]; after I upgraded it, the problem has disappeared (it disables itself automatically when an installation is detected).