Software Title: Ant.com (Video Downloader)
Download Link: https://addons.mozilla.org/firefox/downloads/latest/8174/addon-8174-latest.xpi
Contact Them: http://support.ant.com/home
License: Freeware, Free to use! (Used this myself for YEARS!)
We have used this plugin since 2008-09. I first found this plugin when trying to help my dad out on youtube.
All the rest of the downloaders, had major troubles and didn’t know what youtube had changed.