HIV remains a significant public health problem among men who have sex with men (MSM). MSM comprise 2% of the U.S. population, but constitute 56% of persons living with HIV. Mobile health technology is a promising tool for HIV prevention. The purpose of this study was to identify the desired content, features and functions of a mobile application (app) for HIV prevention in high-risk MSM. We conducted five focus group sessions with 33 MSM. Focus group recordings were transcribed and coded using themes informed by the information-motivation-behavioral (IMB) skills model. Participants identified information needs related to HIV prevention: HIV testing and prophylaxis distribution centers, support groups/peers, and HIV/STI disease/treatment information. Areas of motivation to target for the app included: attitudes and intentions. Participants identified behavioral skills to address with an app: using condoms correctly, negotiating safer sex, recognizing signs of HIV/STI. Findings from this work provide insight into the desired content of a mobile app for HIV prevention in high-risk MSM.