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.
OT: PSP Infinstrip channel strip/rack for desktop released
Announced in January, I think, this is finally out and at an intro price of USD $129 (will be USD $199).
Not cheap by iOS standards but seriously feature-packed if you need/want a channel strip. Many DAWs are, of course, pretty good out of the box (esp. Logic) but it’s PSP...
And the White Sea Studio/Snake Oil dude (not even sure of his name!) likes it: 
(I have no affiliation to PSP - just a sucker for a bargain)
http://www.pspaudioware.com/plugins/dynamic_processors/psp_infinistrip/
Comments
Nice to see this post .. infact I downloaded the demo