A few months ago I discovered Scringo, a framework which allows you to make your Android and iOS apps 'social'. The goal of Scringo is to increase the user retention of your apps by adding social features which makes your uses want to stick around. Scringo does this by helping you to integrate your apps with Twitter and Facebook, it also adds an activity stream and chat room so users can see what is hot and happening inside your app community. However, Scringo goes beyond just adding these social features by means of an SDK. They also provide a developer dashboard on their website allowing you to keep a close eye on what's going on inside your apps. Via the dashboard you can converse with your users, respond to their feedback and send messages to all users informing them of news, updates and new features.
One of the coolest features that Scringo has to offer is the quiz. Via the developer dashboard you can create a quiz, the SDK contains beautiful screens showing your users the quiz and a leader board so all you have to do is come up with a set of questions. The quiz can help you earn some extra revenue by enabling your users to purchase coins which they can use to unlock extra quizzes or to get some help on the tougher questions. My personal experience is that users love playing these quizzes, the leader board is an extra motivator for them to get a high score and keep playing.
I think Scringo is a great way of enhancing your apps with social feature. It really helps you increase user retention, the feature to get in contact with your user base enables you to quickly respond to feedback and harvest new ideas.