Previous user of FireGestures after it broke up with latest nightly I tested this one. Really great addon I like it a lot.
Too bad it doesn't work on addons.mozilla.org and new tab page but it's a web extension limitation. (For the later, thankfully, this addon enable you to change your new tab page)

Please note that version 1.0.6 was not saving changes to settings. Installed 1.07 beta and all is good.