Greasy Fork is available in English.
Adds a MP3 Download button next to the subscribe button, thanks to youtubeinmp3 for their simple download service (http://youtubeinmp3.com/api/). Based off magnus's youtube2mp3 code. Just used something different as it wont open another tab.
Mixed Content Error [SIMPLE FIX]
Just noticed that at the console it returns a mixed content error, due to the image being loaded from http instead of https. To fix this, change http to https :)