UPDATE 11/1/2021: Now you can also skip YouTube ads by watching YouTube videos through the FreeTube app! Available on any computer Windows / Mac / Linux. Not available on mobile devices iPhones / iPads / Androids / etc.
Simply add the word "repeat" in your address bar between "youtube" and ".com" and press Enter.
For example, turn
into
This works great when you really like a song and want to listen to it over and over or you get one of those mandatory 15sec/30sec ads on YouTube.
Enjoy! ^_^