Love it, but beware of deleting it

This game was one of my absolute favorites, I loved it so much that I bought the unlimited version. Recently a bunch of my apps got wiped off my phone, so I redownloaded it. Only problem was that I no longer had access to the unlimited version despite paying for it. I wish there were either two separate apps, one free and one paid, or a type of log in system so that people wouldnt have to repay in case it gets deleted.

parnasses about BEAT MP3 - Rhythm Game, v1.1.9