Rated 5 out of 5 stars

Από τον/την chiappa στις Αύγ. 11, 2015 · μόνιμος σύνδεσμος

I tried the manual about:config method which didn't work. Installed this, works great and extremely useful/easy to use.
I am on version 39.0.3 of Mozilla Firefox for Ubuntu.
Thank you very much!