Cool :) Haven't really run into many on HN familiar with this. We popped up on TC a couple times and managed to get a few thousand users. The cold start problem is tough one to crack though and things ultimately didn't pan out. It's going to be interesting to see how Facebook, Inc. leverages Facebook for Rooms since they have the same problem there.
I also thought of Bunch. We were/are doing something related (but not really) at ReplyAll.me so I had kept track of your company. Were you a dev there?
[0] http://www.joinbunch.com/