It's only extension and when enabled, it directly creates "Download" button over Youtube page. Besides, it saves more hardrive space.
•No need to download or buy any premium softwares.
•Supports HD video downloading.
•Removes popup ads on YouTube videos.
•The first extension to support all browsers and OSxs.
How to Install:
1.Extract and install the extension by downloading following addons.
2.Be sure to enable addons/extensions in your browser.
3.Then open any YouTube video you want.
4.Locate the Download button under the video player.
5.Choose your prefered video format and quality. The download will begin.
Google Chrome 6+
Internet Explorer 7.0+