Mobile applications for depression and anxiety are valuable in low-resource settings with limited mental health services. Engaging users and key stakeholders in application design and development ensure patients’ needs are met, particularly in developing countries. Currently, no mental health applications are tailored to the Ethiopian context. The Design Science Research Method was applied to present the requirements of mental health professionals and usability tests. The results of the study informed essential features such as information on depression, anxiety, and psychological distress; self-care strategies; self-assessment tools; and reminders for medication and appointments. The Cognitive Walkthrough (CW) results showed that study participants liked and agreed with most of the app interface design. Furthermore, closed testing results showed high user satisfaction, highlighting its potential to be widely adopted for other types of mental health conditions in Ethiopia. Overall, this paper provides a comprehensive and methodologically rigorous approach to developing a mobile mental health app tailored to the needs of low-resource settings, with a specific focus on Ethiopia. The research contributions lie in identifying key stakeholder requirements, involving mental health professionals in the design process, utilizing iterative feedback from experts, and preparing the app for real-world testing.