Table 1.

HealthMpowerment 2.0 core components, scientific rationale, and measurement metrics.

Features		Description	Scientific rationale (measurement metrics)
Base app components for all study arms 1, 2, and 3
	Resource center	Multimedia resources and information on health and wellness, stigma, resilience, and life skills—tailored for YBLMTa, inclusive learning styles and health literacy Robust management system to create and tailor new content and activities	Content corresponds to and extends the HMPb 1.0 intervention and aligns with the Integrated Behavior Model (number of articles read and total time spent)
	Test kit ordering	Ability to order and track HIV self-test kit and viral load self-collection test HIV test result image upload to app triggers care navigator follow-up	Provides an opportunity to get tested by reducing barriers to in-person testing (number of test kits ordered and results uploaded to app or received by laboratory)
	Care navigator	Facilitates referral and linkage to HIV services in the participant’s local community Follows up on unreported HIV test results and all shared unclear and positive results Supports app engagement and retention Troubleshoots and triages participant questions within the app to medical, study, and technology teams	Increases intervention tailoring and linkage to care for nonclinic-based study. Provides equipoise and reduces risk of social harms for remote study with HIV at-risk minors. Supports use of self-testing and self-collection for youth (number of questions asked, content of questions, and participant satisfaction)
Interactive app components for intervention arms 2 and 3
	Profile	Personalized, anonymous username, avatar, brief bio, badges earned, and activities completed	Personalization, gamification, and cues to action incentivize engagement (number of times visited and profile sections completed)
	Activities	Activity templates include quizzes, self-assessments, goal setting, choose-your-own-adventure, sorting, and matching	Interactive features will enhance learning, skill building and coping skills (number of activities done and total time)
	Ask an expert	HIV, STIc, sex questions answered by board-certified physicians Care navigator directs participants to on- and off-app follow-up resources	Provide evidence-based answers to participants’ health questions (number of questions asked, total time, and content of questions)
	Forums	Start or add to existing discussions, upload images, videos, memes, etc Favorite posts and follow others Staff monitor and add to forum posts and include polls to encourage dialogue	Forum topics correspond to Stigma Framework constructs. Peer support for resilience and behavior change (number of posts, comments, and likes; total time; content of posts)
	Gamification	Sophisticated tracking of app use to trigger behavior-specific rewards Badges awarded for tracked events	Gamification features incentivize continued engagement (number of log-ins and badges earned)
Peer network referral features for intervention arm 3 only
	Peer referral center	Unique referral code provided to share with peers Participant can track how many of their referred peers have successfully enrolled and then link to their in-app profiles	YBLMT widely use networking sites and apps to socialize with peers. Structural and relational aspects of social networks affect decision making and behaviors (number of peers referred and enrolled, characteristics, eg, size, density, and diversity of intervention networks)

^aYBLMT: young Black or Latino men who have sex with men and transgender women.

^bHMP: HealthMpowerment.

^cSTI: sexually transmitted infection.