mpv support #36

Awesome plugin! I've been using https://github.com/Syncplay/syncplay/ for syncing between desktop players like mpv/vlc, but that lacks browser support.

Came across KoalaSync and really liked the UX.

I'm here to register interest for adding support for non-browser clients. I already have a WIP version in my fork! https://github.com/iamkroot/KoalaSync/tree/mpv/clients/mpv - needs some UI polish, but the core syncing is working perfectly.

Let me know what you think about sending a PR