Show HN: (Couch) Potato Posture Prevention

Like most of you I spend a lot of my time sitting. As I have a hard time keeping an active sitting posture, I decided to spend the afternoon on a small tool/webpage to monitor my posture via the camera and alert me when I'm slacking. As it seemed to work reasonably, I published it online free to use for anyone. (FYI it runs fully client-side.) Enjoy!