Hi all - I made a video of my flight. Here are the steps I took:
1. On Amazon, I bought a mount for my iPhone, a cable to connect the 1/4 in aircraft headset output in the rear cockpit to a 3.5 mm jack, and a cable to connect the 3.5 mm jack to the lightning port of my iPhone. This cost me about $50.
2. Before flying, I made sure my iPhone's battery was full and that it had enough data space available. 1080p video uses about 3 GB/hr.
3. To test the setup, I plugged in the cables, began recording a video on the iPhone, mounted the iPhone, turned on the avionics, and listened to ATIS. Then, I checked that ATIS was being recorded and that the camera view was capturing the windshield and instrument cluster.
4. After flying, I uploaded the video using the YouTube app.
5. In this post, I've uploaded some photos and videos to show how it worked.