This HIV prevention study, supported by the National Institute on Drug Abuse (NIDA), is developing a mobile health application to deliver an HIV risk-reduction intervention. It will test the relative efficacy of intervention delivery via the app compared with face-to-face delivery. This intervention—for young, African American women—is an adaptation of the Women’s CoOp, an evidence-based intervention that has also been adapted globally. In collaboration with local health departments in North Carolina, this study aims to reach women aged 18 to 25 who have not been recently tested for HIV.