Medication adherence is a widely recognized problem that is linked to overuse of healthcare system and negative health outcomes. Among the causes of non-adherence, forgetfulness plays a central role. mHealth interventions are particularly interesting to support medication adherence. Unfortunately, there is a lack of information about the quality and effectiveness of the app available on the market. In this article, we present the design and evaluation of an app for the Swiss market. The app was developed with a user-centered approach and was evaluated by both experts and end-users. The app functions include facilitated medication data entry through barcode scanning, and access to educational materials for specific drugs. Although the evaluation by experts and end-users revealed usability issues, such as the inability to customize the app, and a low evaluation of the performance (subjective assessment), it also found that the app contained most of the core functionalities that are expected for a medication adherence app. These are promising results, and will guide the future development of the app to respond to both experts and user expectations.