Add-ons

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.

User Agent Switcher by chrispederick

The User Agent Switcher extension adds a menu and a toolbar button to switch the user agent of a browser.

DuckDuckGo (HTTPS / SSL) by DuckDuckGo

DuckDuckGo is the search engine that doesn't track you. We also have smarter answers and less clutter. This extension adds DuckDuckGo (HTTPS / SSL version) to the search bar. For more features, see the DuckDuckGo Plus add-on. Enjoy!

Element Hiding Helper for Adblock Plus by Felix Dahlke

Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.

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

Download Status Bar by Szalgiris

If you are the kind of person who likes to have total control over every aspect of your downloads, "Download Status Bar" is the add-on you are looking for.

Linkification by y5

Converts text links into genuine, clickable links...

United States English Spellchecker by jooliaan

This dictionary is no longer maintained.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

Copy As Plain Text by mehtuus

Removes formatting from copied text.

OverbiteFF by The Overbite Project

Add legacy protocol support back to Firefox and SeaMonkey with OverbiteFF, which restores support for Gopher servers, plus CSO/ph searches, finger, whois and more! Cross-platform JavaScript runs anywhere Firefox does.

Raising the Sun by Pistachiocream

Celestia and Luna by chapeauxchick