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.
Music for 18 Apps
Actually there were 27 but that would have ruined the reference.
Another one that’s been on the back burner for a while and has gone through a number of iterations until this popped out. Not in the same universe as Steve Reich’s mid 1970s minimalist classic but it made me happy 😊