Developer Matthias Frick let us know that he’s updated his free MIDI LE app, based on Synthtopia reader feedback, to be backwards-compatible with iOS 7.
MIDI LE is a free app that lets you use MIDI over USB with CoreMIDI compatible iOS apps, without the need for a MIDI adapter.
Onn iOS 8, MIDI LE also lets you use MIDI over Bluetooth LE with CoreMIDI apps.
Note: In order to use MIDI over Bluetooth you need to be using iOS 8.
To use MIDI over USB, your Mac needs to be running a free OS X app.
Frick says that a version for Windows users is also in the works. If you’re interested in beta testing this, contact him at matthias (at) s-r-n.de, or via his site.