Mappiness is an iPhone app that polls users daily with questions about their level of happiness, who they're with, and basic details about their surroundings. This data, coupled with GPS and noise-level readings, is compiled and analyzed as part of a research project at the London School of Economics, one which seeks to better understand how people's feelings are affected by their current environment. The system provides users with data about when, where, and with whom they are happiest, and provides researchers with a wealth of anonymous information.