Tried it for 30 min w iPhone 3G: Looks great, sounds impressive analogue, great and clear (using Sennheiser MM50 headset), stable app. Seems to be the "real" Roland Transistor Bassline 303 enhanced with two nice effects pedals. Quite usable method to move the knobs on a touchscreen. Programming the sequencer like the real thing. Perfect emulation.
I just bought it and had a quick play.. Im quite impressed! it certainly sounds the part so far. No export of any kind, which would have been good. But I guess its just a toy of sorts. Still, its worth the meagre cost
I'll give this a mention in the audio section here.. might get more interest.