The addon itself does it's job very well. However, it is not compatible with the modern Firefox (only for 10~19). Good news is this addon is compatible with Pale Moon 25.1. Installed it and works fairly well. I don't see a way to bring this addon back to the game on Firefox 20+ versions, as the main interface changed, but really nice addon for Pale Moon.
But again, sadly, this addon is one of the "brilliant but adandoned" addons.