Foxy Gestures v1.2.12 
Read the addon description below before installing! There are web extension limitations compared to FireGestures.
Starting with FF60 and FG1.1.1, I've implemented optional permissions for bookmarks, clipboardWrite, and downloads. It means those permission are not required unless you assign related commands. For more information, read https://github.com/marklieberman/foxygestures/wiki/Why-Permissions-Are-Required
Starting with FF58 and FG1.1.0, the OSX/Linux right-click issue is resolved.
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This addon implements mouse gestures for Firefox and is heavily inspired by FireGestures. Foxy Gestures currently implements a large amount of FireGestures functionality:
- Mouse gestures using left, middle, or right button.
- Wheel gestures using gesture button + wheel.
- Chord gestures with configurable chords.
- Configurable gesture mapping with many built-in commands.
- Implement new commands with user provided scripts.
- Configurable gesture timeout and gesture trails.
- Status text during gestures with customizable styles.
- Diagonal gesture support if enabled in options.
Unfortunately, there are many limitations due to limited or absent Web Extension APIs. As a web extension, this add-on will never be as powerful as FireGestures. This extension cannot integrate into about:newtab, about:home, view-source:, etc. Nor will it work on addons.mozilla.com, since web extensions are forbidden from interacting with the add-on store. Mouse gestures don't work until the DOM has parsed.