Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.
Download on the App StoreAudiobus is the app that makes the rest of your setup better.
CsoundPad for iPad
Just saw this on the Synthtopia feed...
https://itunes.apple.com/app/csoundpad/id861008380?mt=8#
Looks awesome and is free.. am going to go play now. 
Comments
Wow, great news! Csound has been around for over 25 years. Great to see it on IOS and supports core midi. There is a quick start guide here:
http://www.csounds.com/manual/html/PrefaceGettingStarted.html
I just found it, and it is monstrous. Already, with the iVCS3 were obtained rather unique sound synthesis for an Ipad, but here, as can be precisely programmed, it will sound to the beautiful sounds, dirty, crappy. It is a pleasure to work on it as much as CsoundPad accept .scd files and can do well and forth and back and forth between the soft Csound (as QuteCSound) and Ipad application.