i’m sure it will come sooner or later but let me just quote Sebastian from Audiobus and what he recently wrote about Midi sync (just to lower your expectation):
"Guys, every developer on iOS currently agrees that MIDI sync is really crap. I’ve basically talked with every single one. They all agreed 100%. We’re working on it.’
And sadly this reflect my own experience.
But i would like to highlight the “we are working on it” part.So,it seems the next big iOS thing is already in development 