What an add-on! One of the most useful add-ons I've ever found. Finally I can block spoilers in YT and can block unwanted annoying channels. But, it's not working with the newer look of YT. You have keep your YT look classic. And for the devs, please I beg to you, please make this add-on work for mobile Firefox, please, please. This add-on is so useful. Thanks a lot guys. :)