Good enough to be usable as everyday mouse gestures addon on GNU/Linux. It workarounds the right click issue on Linux and OSX by replacing context menu with two right clicks and mouse gestures with one. Is not the best solution but as Mozilla seems to disparage non Windows users and treat us as sencond class citizens, developers must be creatives. The settings interface should be improved, as an idea I will made it look like the browsers settings interface, instead those epilectic blues and roses.
Regarding the movements, pretty well, but open links seems not to work at all, and in general any movement on new mozilla pages, like addons (this is known for all addons), 404, speed dial, untrusted SSL webpage, etc