Easy YouTube Video Downloader

 you like video in youtube,use this..

About this Add-on

Add-on to quickly and easily download videos from YouTube to your computer. Adds button to download YouTube videos in FLV, MP3, AAC, MP4 and 720p HD and 1080p. 3GP format coming soon. Full-HD qualities.

New Features :

* Super-fast MP3 conversion speed
* Works within the page (no need to visit external site to download)
* Video-title as file-name
* HD download link visible only when high-definition version is available
* Supports all new 1080p FULL-HD video downloading
* Latest v 3.X works with new Youtube layout

read more source by mozilla, here 

download here