Assegnate 2 su 5 stelle

This addon is not really needed any more, because in Fx 44 (I think also in Fx 43) there is "Subscribe" button in the toolsbar (top right; I not visible then go to Hamburger > Customize and add it).

This addon here also caused a really wierd problem for me: https://support.mozilla.org/en-US/questions/1103412 Just fyi.