In this project, a mHealth tool for smart-phones has been developed using Design Science methodology, where the goal has been to promote an active lifestyle. This was undertaken by implementing social and physical activity stimulating features within the application MoveFit. Users can opt to utilize just a feature or two or engage in social activities of different intensity. Regular and expert users have evaluated the application in order to meet usability requirements. In addition a field expert and a focus group have contributed towards the applications potential to increase physical activity. There was enough data collected by the app to document its good effect; it was possible to demonstrate that the app was capable of promoting physical activity. User testing has also shown the appreciation of the various features such as social networking, activity monitoring, and route/activity creation.