Lol

Best reverse image search add-on for android. It's extremely useful, and adds one of the features I used a lot on android chrome: Chrome's search by image.

The only con would be for the desktop version, where it takes noticeably longer to show the image results than Andreas Bielawski's Reverse Image Search add-on. So although I don't use this add-on for desktop; I do use it for Firefox android.