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.
Apps providing MIDI to OSC
Is anyone aware of a still-maintained iOS app that provides MIDI to OSC translation? I only found TB MIDI Stuff, which is unmaintained and, based on others experiences, crashes frequently in current iOS versions. The best option would be an AU MIDI effect, but I'm guessing AUs can't deal with OSC because they don't have network access.