I don't look at this as an "add-on". I see it as an APP that is a "Must be". FF should have this integrated into every version from this point forward.
The developer is a genius, and a dedicated one at that. The fact that the DEV is still supporting this APP after all of these years demonstrates the dedication to excellence.
I will be sending a "Dough-Nation", (sic) to show my appreciation. If you are using BLOODY VIKINGS!, then perhaps you should donate too.
BIG THUMBS UP & THANK YOU!