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.
Something cool I discovered with Looping and Bluetooth Speakers (GarageBand, LaunchPad, etc)
When using Bluetooth, there's a bit of latency which tends to ruin the flow of the song. Happens a lot when using Virtual instruments, or even music streaming apps such as Spotify.
But, if you use Live Loops on GarageBand or LaunchPad by Ampify, it seems to match up in real time. There's still the initial startup delay, but once you start, it syncs due to Ableton Link. You can change the loops and it will match the tempo of the song. So, you can use apps such as Blocs Wave and there won't be a noticable delay.
GarageBand has its own style of Ableton Link but it follows the same technique. Session View has the delay, but Live Loops will play on queue. So, play your songs in Session View, trim them to loops, then place them on Live Loops and play them live.