This study builds upon a pilot project in which we adapted a positive psychological intervention for mobile app delivery using a just-in-time adaptive (JITAI) design and an ecological momentary intervention (EMI) delivery format. The JITAI EMI uses positive affect induction as an intervention approach to reduce stress and provide “in-the-moment” support to sexual minority men (SMM) living with HIV. Phase 1 of the current study took a community-engaged approach to further tailor the app for SMM living with HIV and comorbid substance use. Phase 2 will assess the feasibility of integrating wearable sensors (smart watches) and random craving prompts as part of the JITAI design, in a factorial optimization trial.