How behind am I? — howbehind.info 
A React web app for keeping count of missed Zoom lectures, since March 2020.
Set your timetable URL and it will automatically add lectures (and other classes) once they happen. When you eventually get around to watching one, just tick it off using the button.
Once you login, your classes are synced through the cloud. You can login with Google, Facebook, GitHub, email, or anonymously.
The frontend is hosted on Netlify with the backend provided by Google Firebase.
This project was bootstrapped with create-react-app. git clone and npm start should be enough to get started.