Mobile health (mHealth) applications (apps) have the potential to support self-management and improve health outcomes in persons living with HIV (PLWH). In this paper, we report on the final step in a three-stage user-centered design process for the development of a mHealth app for PLWH. We conducted a usability evaluation with 10 targeted end-users and a heuristic evaluation with 5 persons with informatics expertise to assess the usability of a prototype mHealth app for PLWH to manage their health. At the end of our usability evaluation, we finalized a Design Document that included the user interface design and functional specifications of the mHealth app. The functional areas which were identified at the end of our iterative process included: Communication, Reminders, Medication Logs, Lab Reports, Pharmacy Info, Nutrition and Fitness, Resources and Settings.