THANK YOU!!!! Working!

Firefox Quantum 以降で使えるこのようなアドオンを探していました。有難うございます。

It even works on Firefox for Android!

This mends the first issue I had (and actually the first thing I noticed) about Firefox 78.

thank you for creating this magic thing ! Save me a ton of time.

Really what I needed: simple, useful, working.
Great work, thanks

Thank you very much for updating! A very needed extension!

simple,but a great addon.
works fine on FF59beta
not works on FF52ESR though.

These simple buttons are so great, I painfully missed them when Firefox Quantum was released. Thanks a million!