Love the app - thanks very much for putting it together and continuing to keep it improving. I've used it to record my laps at Knockhill in Scotland, and you can find a short video with a couple of these here:
I found the app pretty simple to set-up, but quickly moved to external GPS and a fast OBD2 reader to get the results I was after. I've also changed my camera from a GoPro Session 4 to a GoPro 4 Silver to let me use an external mic and get rid of the wind noise you'll find on the clip linked above. I went for a reconditioned GoPro 4 - about 25% of the price of a GoPro 5 or 6 and no need for the expensive adapter required by the newer cameras.
I'm also running the app on a Pixelbook to review my session data at my leisure. This combo produces amazing, professional results, unconstrained by the small phone screen size. Just awesome. Thanks again.