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 Store
Audiobus is the app that makes the rest of your setup better.
The Rattler Redux / How Habits Can Hurt
Thanks to @McD and @JanKun I took another look at this piece. Both these fine fellows had a problem with the drum track. I resisted. I resisted.... but then I listened again and saw I had missed the mark. I was not really hearing the nature of the original track. I just proceeded in my (recently) habitual way... all my tracks need drums (after all, why did I use a metronome when recording?).
But I was wrong... I redid it, removed the drums and added a single DrumJam cello. Less was indeed more. Let all sailors of the iOS seas take heed.... a habit was a good idea dying a slow death. The new, and improved Rattler...