[hprotagonist]

I've been a devoted FF guy for 15 years, so I sure think it counts!

There's a quantum port: https://github.com/gapop/pinboard-webextension (also available by looking through firefox plugins, but i'm linking to the source for clarity)

[faehnrich]

Thank you. I try to go with official plugins, because who knows about all those similar named plugins made by random people. But this one looks legit.