You can try the app here: https://app-healthyworking.netlify.app/. There is also a desktop version of the app (https://github.com/student158/healthyWorkingDesktop).
Sitting too much is bad for your health and developers often sit too much. I made this web app to notify myself to stand up and exercise when I code or study. I hope this app can help others too.
This app uses webcam to detect user sitting. It uses face-api.js for face detection.
There is also a desktop version of this app (Windows). The source code for the desktop app can be found here.
The MIT License (MIT)