I've been using this extension on Chrome for a long time, and love it. So when I checked and discovered that it is available for Firefox, I installed it immediately, and am just as happy with it as I am with Chrome. And honestly, I am getting to the point where I like Firefox better than Chrome! Kinda tired of all the glitches and every update has weird changes that no-one likes, and the mobile version of gmail sucks these days! So goodbye Chrome, hello Firefox :)