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.
Bug report for Poly 2 (LFO Sync Issue in AUv3) along with some other thoughts
When Poly 2 loaded as an AUv3 plugin, sync mode of the internal LFO in each track cannot be actually switched to 'free'. The sync is always on even when the toggle is off.
Standalone app seem to work out fine here.
Do you encounter this issue?
Some other thoughts:
I tried to use Poly 2 sampler as a granular synth by turning on loop then using external LFO to modulate the AUv3 parameters like start point and end point. But it didn't work as I expected.
During the time when a single node is being played, the start point and end point are fixed. In other words, the loop size and position are not changing while the sample is being played.
The end point parameter does not represent loop size, which means the end point might precede the start point if you are using external LFO to control these two not carefully enough. That's when the sound might get quirky and the instance might easily crash.
7-bit accuracy is really not enough for controlling the loop position and size.
These above are hardly complaints for the app, just to show you the work Poly 2 might not do well in.