Skin cancer is one of the most common yet preventable cancers, and overexposure to ultraviolet (UV) radiation is a major cause. The SunWise UV Index mobile app provides access to location-specific information about UV intensity to help users plan their outdoor activities. The app includes daily and hourly UV intensity forecasts and regional maps showing areas of high and low intensity. The daily forecasts are paired with condition-specific advice on minimizing danger from sun exposure. The UV intensity data displayed in the app is provided by the Environmental Protection Agency, the National Weather Service, and The Centers for Disease Control and Prevention. The app is free and is available for both Apple and Android devices.