This is the best extension for marking watched videos. I actually wish I could rate this higher. Everything about it works, the features are more than I asked for. Everyone should get this. -Edit: It almost always works. You can manually hide/dim videos you want. Looks like there is a max of 81 videos you can do for that.

Absolument parfait !! Rien à redire, c'est génial ! Merci !!

Tried several different extensions for marking watched videos befofre I found this one. This is by far the best. Thank you!

Thanks for this awesome extension! It works