[tfinch]

I've used https://www.letsgaze.com/#/ a few times which worked pretty well. Only works with files you have access to, or freely available youtube content though.

I agree that it's a neat idea. I'm sure the content problem is why there aren't more attempts at the moment.

[icebraining]

Thanks for that link! I had found http://syncplay.pl/ but it seems much more fiddly than that.