I´ve been using this extension for years, and I think it´s the VERY BEST mouse gestures addon for Firefox.
On the other hand, my extension stopped working several months ago, being completely unresponsive, thus forcing me to migrate to Gesturefy, which I don´t like as much, but always worked without issues.
It was not until I disabled and deleted this addon and its preferences, reinstall and reconfigured everything from scratch, that I could use it again.
Working great with the latest version of FF as we speak, which is something I haven´t seen in a long time.
Thanks!