Apollo MIDI over Bluetooth Free is a free studio tools plugin developed by Secret Base Design. Compatible OS(s): macOS, iOS.
Apollo MIDI over Bluetooth now has a free trial version for iOS — connection times are limited to five minutes; you can test the app, and see if it meets your needs. The OS X version of Apollo is free.
You can send MIDI between a pair of iOS devices, or between iOS and Mac. We think you’ll be impressed at how fast and responsive the connections are.
http://secretbasedesign.com/apps