It is working and gets the job done Rated 5 out of 5 stars

For all of you saying it's not working, it only adds the button in the menu toolbar (Bookmarks) not the firefox button.
If you want it to be shown in the bookmarks drawer menu in the firefox button i suggest you customize the button menus with this.
Personal Menu (Personal Firefox Button) by Merci chao
goo.gl//eBSrF