If anyone is looking for a free metronome app, here’s one over at CleverParrot software. The source code is there too if you have HB++ running.
Fair enough, this has nothing to do with handheld music making, but I so wish it did. I think that the idea of having a whole environment for creating new effects or synths in your pocket is wonderful. Of course, I have no idea of who difficult something like this would be, but I wonder is it that difficult from latest additions to miniMIXA in terms of modular synthesis?