Introduction <p>Mobile mental health apps provide a potential solution by offering tailored access to resources for mental health education, self-assessment, and self-care. However, mental health apps designed for the Ethiopian setting are scarce; therefore, this study assesses the usability and user experience of a locally adapted app addressing depression and anxiety.</p> Objective <p>To determine the usability of a newly developed ‘Mental Health Solution App’ among individuals with depression and anxiety in Ethiopia.</p> Methods <p>A convergent mixed-methods design was used to evaluate the usability and user experience of a culturally adapted version of the ‘Mental Health Solution App’ in Ethiopia. The study was conducted at Tibebe Ghion Specialized Hospital, and Amanuel Mental Specialized Hospital from January 10 to February 20, 2025. The quantitative strand involved a cross-sectional survey using the Amharic version of the Mobile App Usability Questionnaire (MAUQ) (<i>n</i> = 370). The qualitative strand comprised in-depth interviews (<i>n</i> = 20) analyzed via reflexive thematic analysis, guided by Braun and Clarke’s six-step framework. This design enabled triangulation of usability metrics with user narratives, offering a comprehensive understanding of app functionality, engagement, and contextual relevance.</p> Results <p>The survey involved 370 participants. Of these, 158 suffered from major depressive disorders, while 212 suffered from anxiety disorders. Usability testing of the Amharic ‘Mental Health Solution App’ showed high satisfaction, a mean score above 6.18 on a 7-point scale across ease of use (6.18 to 6.43), interface satisfaction (6.38–6.60), and usefulness (6.31–6.71). Four themes were identified (user experience, feature liking, benefit, and suggestions).</p> Conclusion <p>The Mental Health Solution App’s usability in terms of ease of use, interface satisfaction, and usefulness was deemed very good. Mood tracking and crisis support were the app’s most preferred features. However, it can be challenging to navigate emergency first aid during moments of distress. The findings indicate that a customized app designed for Ethiopian culture and language could help individuals suffering from depression and anxiety within an educated, urban cohort receiving mental health care in Ethiopia.</p> Clinical trial number <p>Not applicable (it is an app usability test).</p>