This is a GREAT download add on for YouTube. I have used it for years and find it to be very useful for downloading mp3 and mp4 formats with different options for file size and download quality. YouTube does not like it's videos downloaded and therefore many developers have a hard time maintaining their applications when YouTube changes their coding to discourage downloading. This developer is constantly maintaining the software to counter YouTube's efforts to thwart downloads. Highly recommended. Easy to use, high quality downloads, and great support. Get it!