http://www.pulsecodeinc.com/rhythmStudio.html
Worth a look for any iOS users. Gonna try it on my travels, £2.99 is peanuts for this even if you just use it as a sketch pad!
Let us know how it goes / sounds.
looks a bit like korg ios gadget but far cheaper (and i expect less capable) … but for the price, you’re right, looks like a great sketchpad. thanks for the heads up!