Just wanted to give my two cents on why this isn't happening for Android. It's the same reason I don't think I'll continue trying to do it, which is unfortunate, because it is a damn good app.
Android's multi-touch API blows, IMO. You can't touch separate View objects at the same time, each touch must belong to the same view. Not only that, most devices only support 2 touch pointers, making a 4-hole ocarina impractical because you can only press two at once. (Though you can achieve a whole scale with 5 holes) Even my damn best-in-class HTC Evo won't process more than 2 pointers on the screen. It's probably do-able to hack something together, but executing a smooth app would be a challenge.