I found some answers regarding both front and back camera usage at the same time regarding AUDIO/VIDEO recording, which is impossible.
In detail here: Can the iPhone4 record from both front and rear-facing camera at the same time?
However, is it possible to use both cameras at the same time to take pictures for iOS?
No this is definitely not possible I'm afraid.
Only one camera session can be used at a time when using
AVCaptureSession
(the lower level API for camera interaction on iOS).If you try to invoke multiple sessions (from each camera) as soon as one session begins, the other will stop.
You could quickly alternate between sessions, but the images will not be taken in synchronicity.