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.
AmpliTube sales
I didn't see these posted here, I figured you would want to know so I put this in Market Place if that's cool... We have three big AmpliTube iOS promos going now...
AmpliTube LE is free for a limited time (normally $2.99/€2.99) - http://www.ikmultimedia.com/news/news.php?id=520
AmpliTube for iPhone & iPad down to 4.99 from 19.99 - http://www.ikmultimedia.com/news/news.php?id=521
AmpliTube ‘All-In Bundle’ for only $/€39.99 instead of $/€99.99 and the ‘All Styles Packs 1 & 2’ Bundle for only $/€9.99 instead of $/€24.99 - http://www.ikmultimedia.com/news/news.php?id=519