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.
OT EZ KEYS BARGAIN
For anyone who has been intreagued by the EZkeys line but put off by the high cost of entry
Gear for Music in the U.K. have 75% off Classic Electrics down from £107 to £29. (Plus p&p).
The good thing being this is the full package not just a sound expansion and comes in a box (even if all you actually get is a serial number).
http://www.gear4music.com/Recording-and-Computers/Toontrack-EZkeys-Classic-Electrics/QE9
I ordered it yesterday afternoon and it arrived this morning so that's pretty good too.