Watch Together by zsb

Browser extension that synchronizes video playback with a friend on any site
that has an HTML video. Two people join the same room and either of them can
pause, play or seek - the other's video follows along.

HOW TO USE

1. One of you presses Create and reads out the room code (e.g. ABC-DEF-GHI).
2. The other presses Join, types the code, and presses Connect.
3. Once you are both in, visiting the same site with any video keeps playback
   in sync. Use the toggle at the bottom to sync This Page only, All
   tabs, or turn it Off.

Room codes are case-insensitive and the dashes are cosmetic, so abc-def-ghi
and ABCDEFGHI both work.

PRIVACY

Playback state travels over a small relay, but the relay cannot read it. The
two of you agree on a key directly with each other and encrypt everything you
exchange, so the relay only ever forwards sealed bytes, and it stores nothing.
It is not even told the room code, only a hash of it. No accounts, no
tracking, no analytics.

A default relay is provided and needs no setup. If you would rather not use
it, the relay is a small Cloudflare Worker you can deploy yourself in a couple
of minutes and point the extension at: popup → Relay server.

Repository and instructions for self-hosting the relay can be found on
Github.