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.
Inter-App Audio Test Video
Here is a quick video of Inter-App Audio in iOS 7 on my iPad 2. There were no rehearsals, it's quick, it's dirty (a little blurry), and ....well.....I ain't no Doug! HAHA Also note there are more apps with IAA then shown in the list in this video I suppose it depends whether it's a node or whatever as to whether it shows up.
NOTE: The one-bar loop issue I had in the video is my fault and is just a setting I forgot to change in Looptical. Looptical works perfectly fine and I hope I didn't imply that it didn't.