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.
[OT] Tip to get multiple midi outputs from 3.5mm midi port cheap and easy
What you can do with these 3.5mm midi output ports is to hook up a stereo headphone splitter on them and then just hook multiple 3.5mm to midi cables on the headphone splitter.
This works with at least beat step pro splitting to 2 outputs, im sure it could handle some more and im sure other devices can do the same.
Im wondering if this would work with normal midi ports by first adding a midi to 3.5mm cable that would be hooked to a headphone splitter that would have multiple 3.5mm to midi cables on it.
Naturally you cant add infinite amount of these, as the signal will start to get too weak at some point.
This will not work going to midi in, midi merge requires more complex circuitry than midi split(thru boxes).
I have one of these from belkin and also bunch of some random 2-way splitters:
Ps. You can also use these headphone splitters as a cv or gate multiple on beatstep pro, like you would use splitter cables. Them being stereo doesent seem to matter. CV outs on beatstep pro seem to be buffered, as it seems to track even when splitted to two different modules. Havent tested splitting to more. They also seem to work in eurorack no problem in general at least with my modules, not sure if some modules have problem with stereo cables tho, i doubt.
Thinking about buying a passive multi module? Think again, as one of these will do the same job, dont waste space in your rack and are cheaper!