First of all, you're posting in the wrong forum. This forum is for threads about existing addons. There is a "Requests" forum for requests/ideas for new addons.
Second, why do you need a mod for this? Shaman totems only affect your party, and you can't give different totems to each party member, so they're much less complicated to assign than paladin blessings. Just say in /p chat which totems you're going to cast, or look at your buffs and see which totems the other shaman(s) is/are already casting. I've been playing a shaman since BWL days, and I can't recall ever thinking "man, I wish there was a mod to tell me which totems to cast!"