Add-ons

DownThemAll! by Nils Maier, Federico Parodi, others

The first and only download manager/accelerator built inside Firefox!

FlashGot Mass Downloader by Giorgio Maone

Download all the links, movies and audio clips of a page at the maximum speed with a single click, using the most popular, lightweight and reliable external download managers.

Spanish (Spain) Dictionary by tnarik, RickieES

Spanish/Spain Dictionary

NetVideoHunter by netvideohunter

This add-on is a downloader that lets you easily download videos from sites like Youtube, Facebook, Metacafe, Dailymotion, Break, VKontakte and music for example from SoundCloud, Grooveshark and from many other sites...

Verificador Ortográfico para Português do Brasil by Vinícius Della Líbera, Adriana Quintanilha, others

Possui a maioria das palavras existentes em português do Brasil, de acordo com o novo acordo ortográfico que entrou em vigor janeiro de 2009. É Atualizado constantemente.

Precisa de ajuda?
facebook.com/RescueLanguage
rescuelanguage.sf.net

Speed Dial by Josep del Rio

Direct access to your most visited websites

Mozilla Archive Format, with MHT and Faithful Save by Christopher Ottley, Paolo Amadini

— Open web pages saved with Internet Explorer or other browsers (MHT)
— Save many tabs, video and audio reliably, in a single ZIP file (MAFF)
— Return to the original site you saved a page from, and more!

United States English Spellchecker by jooliaan

This dictionary is no longer maintained. Use this dictionary instead.

DuckDuckGo on TOR by Ajabep

Search with DuckDuckGo using the TOR network without JavaScript

Brazilian Portuguese Dictionary (Former Spelling) by jhltmnn

The same spellchecker shipped with the Brazilian version of Firefox, just using the former spelling (which is valid until January 1st 2016).

about:addons-memory by Nils Maier

Adds an about:addons-memory page that details add-on memory usage

Linky by gemal

Linky will increase your power to handle links. ...

Video Mouse Wheel by franketto

Use wheel mouse on videos to control video/audio/quality.
Choose flash/HTML5 on YouTube, autopause on background tabs, embedded videos.
And much more!

Cicaszem animated cat eye by Bátja ⃰ ⃰ ⃰ ®

Black Cat Eyes II by Cheddo