Tiltification is a free app that is compatible with Android phones. You can use it to level objects on surfaces. It's very easy to use and you don't need to look at the screen during the process. It works in a very simple way: you place the phone on a surface that you want to level, and then you listen to the sound that is generated by the tilt sensor. You can also use the app to level your objects, and it will tell you the precise amount of tilt that is needed.

It's very easy to use and the app doesn't require any special skills. The best thing about the app is that it doesn't require any special permissions.