The increased use of internet through smartphones and tablets enables the development of new consumer-focused mobile applications (apps) in health care. Concerns including these apps´ safety, usability, privacy, and dependability have been raised. In this paper the authors present the results of a grounded theory-approach to finding what non-functional requirements of medical apps potential users view as most important. A document study and interviews with stakeholders yielded nine non-functional requirements for medical apps: accessibility, certifiability, portability, privacy, safety, security, stability, trustability, and usability. Six of these were evaluated with two groups (differing by age) of potential users through a vignette study. This revealed differences between the age groups regarding the importance each attributed to apps´ usability and certifiability. Furthermore, and contrary to consensus in literature, privacy was considered one of the least important attributes for medical apps by both groups. Trustability, security, and, for the younger group, certifiability, were considered the most important non-functional requirements for medical apps. The implications of these results for developing medical mobile applications are briefly visited
