Mozilla Firefox is a popular browser that has a lot of addons that are available for download. One of the most popular and widely used Mozilla Addons is the NetVideoHunter for firefox browser.
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...you can download NetVideoHunter and install in your Mozilla firefox browser. Download NetVideoHunter mozilla addon for Mozilla Firefox From Addons directory. I am providing the Direct Addon Download link (xpi).