Treballs Finals de Grau d'Enginyeria Informàtica, Facultat de Matemàtiques, Universitat de Barcelona, Any: 2018, Director: Mireia Ribera[en] This project consists in the development of a mobile app prototype for Android in order to record all the daily meals by taking photos or introducing them manually, the nutritional values of each meal is calculated and shown and as a result a healthier lifestyle can be achieved. In order to generate the application, the model DCU has been followed. First, the environmental factors such as potential users have been studied. A market study has been performed with the aim of identifying the potential users that may use the application and therefore, two user profiles have been defined. Then, several similar applications that are currently on the market have been extensively analyzed. The 10 Heuristics for User Interface Design defined by Jakob Nielsen have been applied, the user tests tasks have been defined and user prospective tests have been performed. Taken all together lead us to identify possible usability and design problems. After the mentioned analysis activities, but before starting programming, we have studied the technical requirements for the implementation, libraries and Android versions. Finally, we have implemented the user cases according to similar current market available applications. As a result, a mobile app functional prototype has been created, fulfilling the usability principles, the heuristics in DCU model and it avoids the usability and design errors previously identified.