I'm a day late, but I had this tab open all yesterday, so close enough. Currently working on Fortune, an iOS app. The premise is that sometimes you just need some sort of fortune/pick-me-up/inspirational message. Fortune sends you a random user-submitted fortune at a random time during the day, and also allows you to submit fortunes that will be sent out to users.
Pulling the screen up (http://i.imgur.com/CC5OKar.png) reveals the interface for giving a fortune, while pulling the screen down (http://i.imgur.com/Cm3qgJs.png) reveals the interface for taking a fortune.
It uses Parse.com as a backend, and I'm currently working on reducing the total number of API requests.
One of the problems I'm anticipating is how to prevent users from submitting negative fortunes. I'm looking into doing sentiment analysis on fortunes as they're submitted, but I'm open to any suggestions.