This is a two-arm, randomized-controlled trial (RCT) that will test the acceptability, impact, and long-term sustainability of the Epic Allies intervention application (app), a theory-based mobile app that utilizes game mechanics and social networking features to improve engagement in care, antiretroviral therapy (ART) uptake, ART adherence, and viral suppression among HIV-positive young men who have sex with men (YMSM) and trans women who have sex with men. Subjects will be randomized to either the intervention branch of the Epic Allies app or the control branch of the app.