It sometimes fire backward on any touch after continuous interaction, it can't be fixed until page refresh.
does it need state cleanup and denounce somewhere in the event handler ? Maybe after each navigation or just inbetween any touch events?

This is the extension I was looking for.

I encountered a bug where some time single tap on screen would trigger backward key, I will have to refresh the webpage to stop that from happening.
update: The gesture now feels smooth as silk, thank you for your work!

does the same as the touchpad functions, which are useful on touchscreens

This add-on works wonderfully and added the much needed touchscreen swipe navigation for Firefox on Linux just like what we have with Chrome. I can now use my Surface Go in tablet mode.

thank you for this addon. it works nicely but i have one gripe: the gestures feel reversed. It would feel more natural for me to swipe left to go back (same direction as the arrows point in the gui)

Maybe it would be possible to add a toggle in the settings for reversed swipe directions?

Works great, feels like using Firefox for android.