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.
Random rants about the "Files" app and MIDI timing (no, really!)
I have a user report (including a screenshot) that shows that one of my apps, which has "Application supports iTunes file sharing" and "Supports opening documents in place" enabled, is missing from his "Files" -> "On my iPad", despite the app definitely having created at least one subfolder in its "Documents" folder, and at least one file in that subfolder.
Does any dev here know if this is just another outrageous Apple bug in the Files app, or is there some conceivable scenario where this could "intentionally" happen?