I've had a hard time getting clear instructions on using this interface and so wanted to share an easy way to use your iPhone as a FX unit. In this case I am routing a microphone I have plugged in to input one in and back out of my iPhone.
Here's how I did it, and it works fine.
1. Create an Audio track in Logic (I named my track "iPhone as an Effect Unit")
2. Plug in your iPhone and open the app you want to use as an app (in this case Voice Synth)
3. Add the I/O plug in to the track (it's in the Utility category in Logic). Set the plug-in to go out to output 3 and in through input 5
I have screenshots, but don't see a way to upload in this forum (looks like it needs to be hosted somewhere?)
Hope this helps.