Check out Tweetdeck. It does pretty much exactly what you're looking for with FB and Twitter (and whatever other networks you use). G+ just hasn't opened up an API yet for anyone to tap into it.
I've used Tweetdeck before. Really nice Twitter app, but I don't use FB so there's no need to mesh the 2. My point is, I use Twitter and it serves me well. Without Twitter integration into G+, I have little incentive to use G+. All the friends I care about are already on Twitter, only one or two are on G+. Unless I can read my Twitter feed in G+ in addition to reading my G+ feed, it's pretty useless for me right now. Maybe when they release an API I'll come back and check it out. Thanks for the suggestion either way.