EDUO  Fkeys is a great start, and a good replacement for uControl now that it's been discontinued.

I personally thank the coming of a new utility and eagerly await for it's expanded functionality (as it currently is is useless for me). Personally I hope some kind of solutions springs up where keys in extended multimedia keyboards can be recognized and then assigned to functions in MacOS.

I currently use a Belkin Internet Keyboard (USB) and only three of the bunch of extra keys work. This is for my mother-in-law so for her it's confusing to have so many keys with no use.  
(Version 0.0.5)