This study features a 2-arm randomized controlled trial with approximately 300 young black men who have sex with men (YBMSM) to assess the effectiveness of the 3T mobile app. To be eligible participants will be required to identify as male; Black, African-American, or biracial Black/African American; age 14-19 at baseline; self-identify as gay, bisexual, fluid, or sexually attracted to men; own a smartphone, and reside in any state in the United States. Those in the treatment arm will be provided with the 3T app and those in the control group will be given access to a website with general health materials. Participants will complete brief online surveys at baseline and at 3-months following the baseline to assess effectiveness in changing sexual risk behaviors and communication and condom use behaviors and attitudes.

The overarching aim of this proposed Phase II research project is to fill a gap in prevention by completing the development and establishing the effectiveness of 3T: Tune in, Turn on, Turn up, a multimedia interactive sex-positive smartphone app-delivered HIV and other sexually transmitted infection (STI) intervention designed for use by YBMSM ages 14-19. The larger and longer term aims of developing an intervention specifically tailored to this population, utilizing a technology platform to reach youth where they are, is to contribute to a reduction in HIV/STI risk, increase HIV testing, and an increase in the quality of overall sexual health and relationships among YBMSM. To do this 3T emphasizes partner reduction, avoidance of concurrent partners, use of condoms if having anal or vaginal sex, and getting HIV/STI tests. 3T also focuses on improving quality of sexual experience and relationships, helping participants become clearer about what they do/don't want to do sexually, communicating their choices, and learning ways to enhance sexual experience without increasing HIV/STI risk. dfusion and its research partner, ETR, will meet the following specific Phase II aims:

• In conjunction with advisory panel members, develop content and corresponding storyboards for all activities. The curriculum will include content on risk reduction, sexual health and the quality of sexual experiences, and developing healthy relationships;
• Successful development of the first mobile app-delivered STI/HIV prevention program specifically designed for YBMSM aged 14-19. Reaching this aim requires continued development of the app technology, including the multimedia interactive activities, games, data collection, activity randomization, and an asynchronous forum. Research shows that YBMSM use the Internet to find information related to sex and sexuality, find friends and sexual partners, and YBMSM are increasingly using mobile apps, such as Grindr, to meet sex partners.20 The reliance on mobile devices for education and entertainment make it the ideal technology platform for reaching the YBMSM audience;
• Conduct a rigorous evaluation to determine the effectiveness of the intervention to reduce HIV/STI risk.

The evaluation features a 2-arm randomized controlled trial with approximately 300 young black men who have sex with men (YBMSM) to assess the effectiveness of the 3T mobile app. To be eligible participants will be required to identify as male; Black, African-American, or biracial Black/African American; age 14-19 at baseline; self-identify as gay, bisexual, fluid, or sexually attracted to men; own a smartphone, and reside in any state in the United States. Those in the treatment arm will be provided with the 3T app and those in the control arm will be asked to use a website with general health information. Participants will complete brief online surveys at baseline and at 3-months following the baseline to assess effectiveness in changing sexual risk behaviors and relationship and communication behaviors and attitudes.

Recruitment. We will use multiple methods to recruit participants: 1) Engaging Organizations. Approximately 15-20 organizations from across the U.S. that serve YBMSM will be approached to help recruit participants through social media and in-person 2) Using Social Media Advertising including targeted advertising on social media sites and sponsoring study posts with social media influencers in the YBMSM community.

Inclusion Criteria:

1. self-identification of being aged 14-19;
2. ownership of an iphone or Android smartphone
3. self-identification of racial identity as black, African American, or biracial; and
4. self-identifying as gay, bisexual, same gender loving, or sexually attracted to the same gender.
5. capacity to assent, based on formal assessment
6. a willingness to participate after complete understanding of the topics of study, as indicated by a completed assent form
7. resides in the US

Exclusion Criteria:

• Anyone not meeting inclusion criteria

self-identifying as gay, bisexual, same gender loving, or sexually attracted to the same gender

Participants are randomly assigned to their condition without being made aware of their assigned condition as "attention control" or "intervention." Each condition accesses materials online.