StormTracker 21, developed by WFMJ Television Inc., is an Android weather app that provides its users with the latest updates on weather conditions. It is a free app that offers access to station content specifically designed for mobile users. With its 250-meter radar, it has the highest resolution available, which enables users to track severe weather, including storms and hurricanes, with ease. Additionally, the app offers high-resolution satellite cloud imagery, current weather updates, and hourly forecasts, which are updated regularly from computer models.

The app also features a fully integrated GPS, which helps users stay updated on the weather conditions in their current location. It also allows users to add and save their favorite locations, making it easier to stay informed about weather conditions in places they frequently visit. Furthermore, the app provides severe weather alerts from the National Weather Service and opt-in push alerts to keep users safe from severe weather conditions.