Socialize spontaneously with mobile applications

With the proliferation of mobile devices in both smartphone and tablet form factors, it is intuitive and natural for users to socially interact with their collaborators or competitors in multi-party conferencing, productivity, or gaming applications. In this paper, we make a case that such social interactions should be much more spontaneous to users in these applications. We design and implement a new system framework, Reflex, to provide the required system support to achieve spontaneous social interaction with other users in the same mobile application, be they in the same living room or around the world. Reflex features a simple and intuitive application programming interface (API), and uses cloud computing services from Google App Engine to offer the scalability and performance required to support spontaneous social networking at a large scale. Reflex is able to transparently switch to local interactions over Bluetooth or Wi-Fi interfaces, available on mobile devices, whenever possible. In order to evaluate Reflex in the iOS platform, we developed a real-world music composition application, called MusicScore, from scratch on the iPad, which takes advantage of Reflex to let music composers collaborate in real time.