Firefox add-ons really add value to the browser by providing useful functionality that eventually help users, but setting up extensions on a new Firefox profile is really painful, this could be on your own PC or another PC that you are using.
There are several tools to backup Firefox bookmarks and settings or for that matter backup everything in Firefox and restore it, another useful and handy Firefox add-on called Mass Installer aims to solve a problem many of us face while installing your favorite add-ons in a different profile or new install of Firefox.
Mass Installer allows users to install a bunch of extensions with one single click, if you work at many different places or clean your profile frequently, you’ll be hunting and installing extensions more often than necessary.
Mass Installer tries to simplify this task by providing you with an option to specify a link to a local or online file which contains the list of extensions you want to install, this file may contain the link to the XPI of the add-on, one on each line.
To mass install extensions, open the options of Mass Installer and provide the location of the file, it should then install all the extensions listed in the file.