Eine recht interessante Lösung für ein "Problem", welches vorher noch keins war. ;)
Aber es ist gut und tut was es soll. Praktisch.

прикольно мне понравилось ) работает вроде как

I would like to report that this add doesn't work correctly anymore(( The line is lagging or doesn't move. Or the line is already full filled but the video is just started. Could you fix it please? Coz it was great solution for youtube at first)

Does what it needs to do, you don't even need to set it up!

works great, but needs too much permissions – this addon is not open source, so you can only wonder…

Very very nice! Do you have this plugin as a user script? That way I can figure out how to change the color of the line :)

Edit:
Jesus christ man, I am very flattered!
Thank you very much for your hard work!