This paper focuses on the use of mobile “app”-based interventions as tools to influence health-related behaviour. Apps are software applications designed to run on smart phones and other mobile devices We review the extensive but fragmented literature relating to serious games and gamification in order to identify the key concepts and frameworks that can be used to underpin the design and evaluation of these apps. We then use these criteria to review a range of current apps developed by one public body, the UK NHS and commercial developers of health-related apps and compare these to commercial apps promoting unhealthy food items. We suggest that there are serious weaknesses evident in the apps provided by public bodies and that this sector could learn from an analysis of the development strategies used in the commercial sector. Directions for future research conclude the paper.