Thanks for your comment.
To answer your question: an android version is one of the options on our to-do-list for further development. Lot's of resources, assets, work and energy have been invested so far to realize this App, if it was up to our motivation only, we were already heading for Android as well...
Since we have just released the first version of Drumtune PRO for iOS, our current focus is on supporting this version, and on firing-up the launch and sales.
Perhaps later on Android will follow, of course depending the success of Drumtune PRO for iOS.