We investigated pre-exposure prophylaxis (PrEP) uptake, adherence, and discontinuation among young app-using men who have sex with men in California (N= 761). Approximately, 9.7% of participants had ever used PrEP; 87% of those deemed good candidates for screening (indicated by a Centers for Disease Control and Prevention risk index score≥ 10) were not current or past users. PrEP use was associated with higher income [adjusted odds ratio (aOR): 4.13; confidence interval (CI): 1.87 to 9.12], receptive condomless anal sex (aOR: 3.41; CI: 1.71 to 6.78), HIV-positive sex partners (aOR: 2.87; CI: 1.53 to 5.38), popper use (aOR: 3.47; CI: 1.96 to 6.13), and recent sexually transmitted infection diagnosis (aOR: 2.90; CI: 1.64 to 5.13). Some users (41.5%) wanted help remembering to take PrEP. The top reason for discontinuation was concern about long-term side effects (33.0%). Young men who have sex with men app users are prime candidates for PrEP, despite low uptake. Apps may be useful tools for PrEP information dissemination, adherence monitoring, and support.