I started using this add-on after another add-on that I was using to download you-tube video's was no longer available. I was formerly using down-them-all as a download manager in conjunction with another add-on. This add-on works well to download video's and mp3's from you-tube, with an easy drop down menu under the video. My only critisisms is that if you pay for the paid version, but then clear your cookies and try to download an mp3 it will tell you to buy the paid version again. The easy fix for this is to keep the activation email you are sent when you first pay for the add-on, and click on the link inside it to re-activate.