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.
After 6.0.1 iOS update, everything is buggy
Things were working pretty good recording into both Loopy and MultitrackDAW from Sunrizer and the like, and then I was clearing off space, and decided to hit the launch button to update my iOS to 6.0.1. The record button on the Audiobus bar failed to appear at first. Then I couldn't find Multitrack DAW at all when I clicked on the output button of Audiobus. I reinstalled Multitrack DAW at some point and it works better, but not as slick as it once did. Loopy is failing to record all the audio sent to it now as well. It cuts out for periods of time.
I got a crash at one point before noticing this that popped up a dialog telling me I had encountered a known issue in the iOS audio subsystem. It sent a support e-mail on my behalf. I was told to reboot or at least restart all the apps, so I figured it was a one-time thing. It may even be unrelated to the other issues I'm having.