Here's a nice sounding trance track made entirely on an iPad by Software Developer Rodi de Boer (@RodideBoer on Twitter). Here's what Rodi says about the apps he used (from the Soundcloud page for this track):

This is made on an iPad 2 with NanoStudio as the base. Sounds come from NanoStudio, BassLine and Addictive Synth and I used Hokusai for some sample editing when I got it to do what I wanted. Drum sounds come from layered and edited NanoStudio TRG samples.