Extensiones que considero imprescindibles y buenas para empezar.
The easy way to download and convert Web videos from hundreds of YouTube-like sites.
An extension that allows Firefox to connect to websites using different user names. Simultaneously.
*** Multifox 3.2.1 available *** Get from https://getmultifox.com/ while Mozilla does not review it
*** Multifox 2 users: try the "Window Mode"
Expand your email area by blocking and removing ads on the right hand side of the screen when using Gmail, Hotmail, Outlook.com and Yahoo Mail.
Personas are free, easy-to-install "skins" for Firefox. Personas Plus extends that built-in functionality to give you even more control and easier access to new, popular, and your own favorite Personas.
Multi Links lets you open, copy or bookmark multiple links at the same time rather than having to do them all individually.
Bring back your personal and powerful Firefox Button!
My Homepage is a very useful extension which loads your Home Page whenever you open a new tab.
Adds extension options dialogs to the Tools or Titlebar menu and includes toolbar icon.