Mobile applications (apps) supporting individual users in their personal fitness have received growing interest on the user side and in the research community. The value offered to fitness app users in general consists of support for changing attitude and behaviour towards a healthy lifestyle and maintaining this behaviour. Work presented in this paper aims at contributing to this field by focusing on the following main research question: what improvement potential exists for fitness apps that at the same time are contributing to the business model and desired from a user’s perspective? The contributions of this paper are (1) market and functionality analysis of fitness apps, (2) results of expert interviews on functionality and scenarios with business model improvement potential, and (3) results of a user study on desired improvements from a usability perspective.