Now the Noise IO manual is available, so it can’t be too far around the corner right?
This looks like an interesting application, and reminds me a lot of SpinPad from miniMusic. I think that this could be quite interesting depending on how much control you can take over the sounds themselves.
A couple of apps that I hadn’t noticed at all called miniPiano and FingerPiano. The web sites supporting these are in Japanese so I can’t tell you too much about them except show you the videos.