BarSense - use computer vision to analyze your lifts and improve your technique
barsense.com
barsense.com
It was unclear for me how the tracking is done. My first thought was that I had to mount the phone to my arm or the bar. After following the link to the play store, I see that it tracks with the camera.
Watching yourself lift from the side is great, even if not using this app. I recommend having someone film you or put your phone on something. Personally I have discovered that I didn't end with the bar straight up when doing bench, and that I should go deeper on squats.
Edit: Clicking the "coming soon on app store" displays a form flickering and then "[object Object]". Fx 26.0