Not intuitive - doesnt work for shi....

I cant figure how how to use this, or its not working on my phone. Im running 10.0.2 and it doesnt do much of anything. Ive read that the developer is not supporting it and the last update was 2014. Why is it still on iTunes. I cant find any documentation so I just through my money away.

Monty son about Rhythm Calculator - Advanced rhythm trainer and metronome, v2.1.2