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 genius of Vi Hart
Vi Harts youtube channel is a wonderful place for math nerds, artists, and musicians. I have followed her for years. She is a treasure.
With all the recent innovative apps from developers like @pagefall and @brambos (Mosaic), as well as the number of wonderful fx apps, it would be interesting to see some of these concepts brought to life on iOS.