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 StoreAudiobus is the app that makes the rest of your setup better.
What matter of developer are you who can summon up sounds so ferocious?
I... Am a Groove Rider...
By what name are you known?
There are some who call me... Jim... Audio...
Just recently got into Groove Rider, the praise of it I've come across is justified. That developer name though, does "Jim" stand for something? Or is it just a guy named Jim? When the app opens it always makes me think of this Monty Python scene. 
Comments
It's Jim Patloff. And, he is a badass sound designer.
Watch this video of Jim, the creator of Groove Rider, remaking a Prodigy song. It has over 3+ million views. Because, he's good at music & stuff.
FML.. I guess I may as well just stop now...
I wish every dev could put in as solid of a year of helpful improvements and updates following release that Jim has managed with Grooverider. I don’t think there’s a better example of an app receiving sensible feature additions
No reason to let that intimidate you or discourage you, nor should you view what he did there as some sort of standard. Some of the greatest songs ever written are firmly rooted in simplicity.