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.
Comments
Having done pro setups for decades myself I would give Rich’s detailed setup info at Ibanez Rules my “Best of the Internet Award.”
http://www.ibanezrules.com/tech/setup/index.htm
Also noteworthy is most anything by Stew Mac luthier Dan Erlewine
I scanned a few of those, and they seem pretty good.