Awesome extension. My experience has been excellent.Hope it would continue in future too.
This is very best extension as for as you tube downloads are concerned. I recommend this to all users of firefox.
However in recent months , may be for about 4 to 5 months not working, It always says that it has been blocked by youtube. Even though button shows to be active and when pressed says it is getting connected but gets the video in mp4 or mp3 version.
Let us know what is the problem. Some people reported even after paying money bought the app for it, it does not work!! Really bad. I saw that site YT1s works well, then why not this app , which many YT users depend on.