Antiretroviral therapy adherence remains challenging for many people with HIV. To overcome this challenge, we created and tested CHAMPS, a combination intervention comprised of a novel mobile health application (app) and community health worker sessions that monitor and manage HIV medication adherence. This study assessed the usability of the CHAMPS app. Results showed user satisfaction and perceived usability of the CHAMPS app, suggesting that the rigorous user-centered design supported a usable app.