Love the App, really inventive piece of stuff, i do music producing for a living, and im always on the go, 'psp kick' has been a really good time filler, getting down ideas quickly etc. Infact, because of using psp kick, i came up with a useful melody which i will use in a track im currently producing. Way to go guys!
The pattern/song feature reminds me of Fruityloops, nice touch.
Anyway on with the questions.
I dont know if its possible with the limitations of the psp hardware, but some kind of delay/reverb effect would be extremely useful, and i think it would be a better idea to integrate a piano roll feature (much like cubase, logic) to lay down notations. This will speed up creativity.
Again, nice job to all the developers, and keep grooving on you psp kick lovers!