Rated 1 out of 5 stars
Alleged to work with Firefox 24 and up, but not compatible with Firefox 28 Mac — no toolbar button, therefore not usable at all. Like quite a few Firefox add-on developers these days, this gent has not bothered to test his brainchild properly.This review is for a previous version of the add-on (188.8.131.52-signed).
Thanks for reporting. You'll understand that not all developers have enough time and/or money to test on all combinations of platforms and applications. They would be helped with more user feedback. All I can see in the add-on statistics is that 7% of the current users is on a Mac and about 10% is using a Firefox version older than 29.
I have encountered other add-ons that caused issues with toolbar buttons in the past. Before Firefox 29 was released, every add-on had its own code to manage these buttons. A solution would be to install Firefox Developer Edition besides Firefox 28 and to use it to test or use add-ons that require (or work better) with newer versions of Firefox. This should be unproblematic because the Developer Edition has a separate user profile.