To be up front I've no idea what add on are. I'm trying to find a way to add a program I Was given for "time warning" on, Chess.com. But like they said. This is easy to use.

Doesn't work on modern Android phones with Firefox for Android

Best in class, and works best with firefox. Love it :)

Gee, this whole experience is so exciting and at the same time overwheing for me. I dreamed of having an internet experience like this but I didn't know that it Tally exisisted. It is so vast it's going to take some time for me to understand, comprehend and utilize. But I'm living and loving every moment

Possibly the all-time best extension for Firefox. Essential for anyone who values privacy and browser performance. Yuge thanks to the developers.