The key for successfully deploy mobile applications is the ability to understand the specific needs of its customers. In the field of mobile health monitoring, the currently most important user group is the group of persons of the age 50+. In our project senSAVE® we developed a user interface for monitoring personal vital parameters that is specifically adapted to the needs of this group. The paper illustrates our work to ensure usability of the application and the outcome of the project. Keywords Mobile health monitoring; Elderly assistance; Gerontechnology, Wrist phone, Disabilities.