KIU! is an online HIV prevention program for young men who have sex with men. The platform was designed to enable wide-scale dissemination of digital health interventions. The platform makes it possible for multiple organizations to implement KIU!, while enabling each individual organization to customize content, branding, resources, and email reminders, as well as manage participant enrollment and data collection for their site. KIU! utilizes video, games, animation, and humor to enhance engagement and encourage positive behavior change. It also features interactive tools and activities based on real-world scenarios like dating and meeting people through apps.