Great add-on, but... Rated 3 out of 5 stars
The add-on is very useful and I really like it. But as some guys already mentioned, the icon in the add-on bar is kinda annoying. Sorry, mate! You've done an almost perfect job, for sure!! But imho it's not 100% perfect until you give the users an opportunity to decide themselves how to use it. I mean, if everybody would make add-ons, that add some icons to the add-on bar or somewhere else, a lot of people would just stop using them. I guess, it's in your own interest to improve your project. I'll remove your add-on for now, because I want to keep my add-on bar clean, but I'll try it again. But hey! As I already said: great job!! Respect!
Edit: Come on, I just gave you a respectful hint, so that you can improve your add-on. I mean, of course it's totally okay, if you don't want to act on other people's suggestions - your decision! But you don't have to tell me about "the concept of the add-on bar" - it is just how you understand and use it...
Btw: I tried it once again and I think staghavi is right. It really slows down tab switching. There's another great add-on, that has neither the nuisance with the icon nor the tab switching problem... You can find it here: https://addons.mozilla.org/de/firefox/addon/youtube-bogus-remover/?src=search
What do you use your add-on bar for? If it is completely clear, you should hide it. If it is not, why do you care about having an extremely small icon there to configure my add-on.? That's why the add-on bar was invented, to allow add-ons to show configuration options. I mean, I can understand that you don't like the concept of the add-on bar at all, but you can hide it in that case.