I love this add-on! Many times there are YouTube videos that I want to save because they have information that is important to me. This gives me a way to keep them stored on my local computer, and I can access them without worrying that they will be deleted.

UPDATED: I think I've been using this add-on now for about 8 years! It's still fantastic, and able to download videos from anywhere I need them. And it saved my bacon this past week, as I went back online to a DIY site that I'd visited in the past. I wanted to look at a video on some construction techniques I needed. But the video was gone from the site! Then I remember I downloaded it with this program a few years ago. Took me a while to find it, but it was still on my backup drive! If I hadn't had this program to download it back then, I'd have never been able to watch it again!