glad to hear it!
modup(s) is now working for initial release — it currently only handles buffs, i'll add support for debuffs tomorrow.
it's probably more of a niche addon and certainly isn't a required element of modui. it acts a little like a very stripped down and super-lightweight PowerAuras (or the Spell Activation Overlay art frames that show in retail WoW with certain spell procs) by showing text symbols when an aura (defined by the user in the addons list file) is applied to the player.
here's what it looks like when I have the fear ward buff:
or renew:
or both!
the system for adding more buffs to track is lua-based and
here, with a (hopefully) easy to understand set of documentation.