This is the GitHub repo for the FirebaseRTC codelab. This will teach you how to use Firebase Cloud Firestore for signalling in a WebRTC video chat application.
The solution to this codelab can be seen in the solution branch.
See http://webrtc.org for details.
Editor's note: I followed this Codelab, but there were some issues I had to figure out on my own, with a little bit of help from elsewhere
I did this mainly as a way to help teach myself javascript, as well as getting a bit of experience with WebRTC, as I had plans to use the WebRTC library to help with another project of mine, that being the Fitbit HUD, in which I plan to use my Fitbit Versa 2 watch (along with a 3d printed chassis to hold all the components together that I plan to design in the future) as a Heads Up Display (HUD). My plan with this in this case was to utilize the WebRTC library to manage communication between the Fitbit Versa 2 watch app/companion (what runs on the phone) app and something along the lines of a Raspberry Pi Zero W 2 and/or a ESP32 camera so as to stream the camera's picture data to the watch and potentially add (an) overlay(s), along with other features (such as zooming in; actually, the original inspiration for the whole Fitbit HUD thing was because I wanted to be able to "zoom in" my vision in class to get a better view of the board, lol).