I've had nothing but problems with this extension since I installed it. I've had no issues whatsoever with udl helper now

mp3hub.com is for sale therefore this extension no longer works

I don't understand the point of this extension. I installed it and when viewing a video on YouTube that I want to save an mp3 of the music from, I click on the MP3hub link below the player. All it does is to open a new tab of the same YouTube video. When I go to mp3hub.com and put a link to the YouTube video in the provided URL box, all it does is to go to that same YouTube page. Nothing is downloaded.
So thus far, it's a useless extension.