The best extension for Firefox. You can change the speed of the video for any value you want, like 0.9 1.2 1.3 and even beyond the limit, going to 2.2 2.5
That's my favorite feature.

I simply would not be using Youtube at all without this App. Tanks guys

Fantastic extension that automates so many settings and makes my YouTube Premium experience even more premium. Be it actively watching videos or playing music in the background while working or driving, I cannot imagine getting a good experience without this addon. Thanks to the kind folks behind it. Yes, there may be some bugs but this add-on deserves 5 stars.

best

Increased my YouTube experience 10fold.