MIDI LE is a simple utility to deliver the experience of low-latency MIDI over Bluetooth LE to CoreMIDI compatible iOS-Synths and applications. To achieve this, MIDI LE is routing the virtual ports of supported applications to Bluetooth. If your favourite application was working with MIDI over WiFi in the past, it will most likely work with MIDI LE.
Bluetooth over MIDI is a newly introduced feature in iOS 8 and a forthcoming feature of OS X Yosemite 10.10.
For more information please check out the support page.
An upcoming update will revamp the UI, add settings and include iOS to iOS Bluetooth MIDI compatibility.
And what’s more, it’s free.