In this paper we present the functional features of a mobile Personal Health Application that aims to empower Type 1 and Type 2 diabetic patients by facilitating self-management of their disease. The application supports the collection of observations of daily living i.e. vital signs, diet, quality and quantity of sleep, physical parameters such as weight, mental parameters such as self-assessment of quality of life, level of mood and stress, and physical activity related information. The application can operate in stand-alone mode as a consumer health app running in smartphones and tablets. However, the full range of its functionality is available when integrated with a server-based patient empowerment framework that further facilitates diabetes management with the active involvement of healthcare professionals, the exploitation of inclusive knowledge from clinical guidelines, and the incorporation of comprehensive information material.