Very good extension, simple but works fine. Most importantly, it supports diagonal gestures, which had been a huge problem since Redox Mouse Gestures were discontinued which made me to run to great lengths to find some workarounds to keep it alive. There's one substantial drawback, though. The add-on does not support gestures in Firefox windows, which wouldn't be a huge problem, if it wasn't for the fact that the gestures don't work in each new tab. I've got a solution for it, too, though, but it will be satisfactory only for those who want to set some specific website as their home page. Just download "new tab override" extension. Anyway, it'd be nice if the author of the add-on could fix the problem, making it a five-star affair.