Only support Android 5. 1+ Dual Sims Phone due to Google native support. Any prior to Android 5. 1, do not use it. Ringtone Randomizer is easy to use. It allows you pickup any song file as a ringtone. Just a few steps you can set up playlists of ringtones, and get different ringtone after each incoming calls. Fast and light app. Support unlimited ringtones.