Firefox addon to synchronize any video playback between friends.
Supports basically every website, not limited to, but including:
Currently known websites without support:
If you want one of the final releases just simply take the xpi file and drag'n'drop it into a Firefox window.
If you want to use another version from source code you will have no chance to install it permanently into a normal Firefox. None whatsoever. But you can temporarily install it by typing about:debugging into the address bar, pressing enter, going to "This Firefox", clicking on "Load temporary add-on..." and then selecting the "manifest.json" that you got from cloning this repository.
By default the addon connects to the linkplay.softwar3.com server but you can change that in the extension settings.