Yes, you can use EpocCam to enable an iPhone/iPad as a webcam on Mac or PC. But how do you mount the thing so you’re not looking up the user’s nostrils?
I took a bit of Meccano and attached it to the top of the back of my iMac with 2M Command adhesive strips & added a powerful magnet from my Sugru with magnets kit.
Then I placed the iPhone into a case that has a steel plate attached to its back (normally used in to car on another magnetic mount). Then I positioned the iPhone in landscape view (the only orientation that works with Epoccam) with its edge sitting on top of the iMac. Then I adjusted the angle of the Meccano plate until a suitable position was achieved.