Comparing Mobile Health Strategies to Improve Pre-exposure Prophylaxis Use (PrEP) for HIV Prevention

Inclusion Criteria: * Self-identifies as a cisgender man, transgender man (assigned female at birth, trans-masculine spectrum), or transgender woman (assigned male sex at birth, trans-feminine spectrum) * Report sex with a cisgender man or transgender woman or any individual assigned male sex at birth in the past 12 months * Age 15 years or older * Willing and able to provide written informed consent * Owns an iOS or Android mobile phone and able to access the internet and send and receive text messages * Able to understand, read, and speak English or Spanish * Newly initiated PrEP or currently on PrEP and at risk for PrEP discontinuation based on at least one of the following: * Initiated PrEP within the past 6 months, or * Has any of the following risk factors for PrEP discontinuation: missed clinic visits; age \< 30; African-American or Latino; transgender gender identity; or self-reported illicit substance use Exclusion Criteria: * Currently enrolled in another PrEP intervention study * Unable to complete 12 month study participation * Any medical, psychiatric, or social condition or other responsibilities that, in the judgment of the investigator, would make participation in the study unsafe, complicate interpretation of study outcome data, or otherwise interfere with achieving the study objectives.