The only simple mouse gesture add-on that is small ~38KB. All the other add-ons with mouse gesture and gesture line (display) are above 500KB!

Works much smoother than Foxy Gestures even with default settings. Yes, you can't customize gestures, only turn them off, but since they are default Opera gestures, i'm completly fine with it. If you are a former Opera user who used default gesture settings - this extension should be your choice.

Awesome!

But is there a way to enable it on sites like this one (addons.mozilla.org) and on about:newtab and other about: tabs?

Doesn't work on "New Tab" page; can't switch tabs with mouse wheel when hovering on tab bar.
Otherwise a very handy add-on. Thanks!

works well, as on opera :)

Doesn't work on Linux (Fedora 29, Firefox 65.0.1).
Menu timing OFF: some gestures work but contex menu opens the same time.
Menu timing ON: nothing works.