Seeking Best Drum Programming App

Hi All!

I've been searching around for a good drum programming app. I'm a composer and would like to start composing on my ipad. I'm seeking an intuitive app that doesn't have a huge learning curve, but that also offers good results. Does this exist? My preference is to use non-kit type drums, i.e. native/world drums, percussion, industrial sounds, other more unusual drum sounds, as opposed to standard kit sounds. Does anything exist like this? Or at the very least, kit sounds that can be major tweaked to sound otherwise. I have not been able to find anything personally. It would be awesome if Roland released an app version of their Handsonic 15 unit! That machine rocks. I create indie/artistic/atmospheric rock and also soundtracks.

Ideas?

Thanks!

nervx