Gesticulate by squib

Gesticulate is a work-in-progress add-on that supports rocker gestures to execute common browsing tasks.

Help! This doesn't work on Mac or Linux!

First, make sure you have Firefox 58 or greater. Then go to about:config and set ui.context_menus.after_mouseup to true. This will ensure that when you start a gesture with RMB, you'll be able to complete the gesture instead of being interrupted by the context menu.

Supported Gestures

RMB->LMB: Go back
LMB->RMB: Go forward
MMB->LMB: Previous tab
MMB->RMB: Next tab