These holidays I've been working on this side project. I learned a ton and I think it has some neat little features to show:

    - It's a React application written in TypeScript using Parcel[1].
    - No back-end. Data is shared via WebRTC directly between connected browsers. I'm using Yjs[2] to help me with that.
    - Synchronized timer and YouTube player (audio only).
    - It isn't responsive yet and lacks some polishing but I did put several hours on tweaking the UI. Things like volume slider being logarithmic instead of linear, high precision timer display using request animation frame (so no longer/shorter seconds) and force/sensitivity aware volume scrolling with both mouse wheel and trackpad, among others.

I started using it in my current job and my team is super happy with the experience. Still have some work left to do though:

    - Actions and comments.
    - Different user roles, so only select people can control the timer, music, etc.
    - Data export.

Feel free to leave feedback here or on GitHub[3]. Perhaps it could be helpful to you as well. Cheers!

    1. https://parceljs.org/
    2. https://docs.yjs.dev/
    3. https://github.com/haggen/hindsight