Very good, but lacks some options.
For me, one of the best battery application from the Apple Store, except for the lack of choice to use MIDI, and integration with GarageBand, which would make this app the best follow-up.
Another point is that we are not updating for some time and also on user comments, I see developers do not reply in any of them.
RoniFoca about
Drums! - A studio quality drum kit in your pocket, v3.1.2