Does exactly what it says in the description. Downloads videos in a snap. also allows you to choose the format you would like the video in. No adds+ dont have to use any other software++ free+++. this add on is the reason i use firefox. there are plenty of good browsers out there now. i used to use firefox exclusively a while back and then swapped over to others for a bit here and there. this add on made me come back. i do intend on making a donation for this add on in the future. Oh yeah another reason i like this is that i have not been haunted by pop ups asking me to buy donate or register. this add does what most standalone apps people pay for and does it better.