Looks a lot like my app: http://www.thetaboard.com

But with some more bells and whistles and a predefined PM workflow.

(In fairness, we both look like Pivotal and Trello to a lesser degree so it doesn't bother me)

Given the noticeable similarities, I'd love to hear how you get on with signups and revenue. ThetaBoard is currently free (It's hard to compete with Trello's price!) but I would certainly love to make a living with it. I've just found it very difficult to "market" something that is designed to appeal to such a broad market.

Good luck with the launch.