Sun Tran is a free Android app developed by Sun Tran in Tucson, Arizona. The app is designed to help users navigate Tucson's bus and streetcar systems with ease. With Sun Tran, users can access real-time arrival predictions, track the current location of their bus or streetcar, and view how full it is before arriving at the stop.

The app also features an interactive multi-route map, allowing users to locate the nearest bus or streetcar stop and plan their trip accordingly. Additionally, Sun Tran keeps users informed with service alerts and departure times, as well as stop reminders. Overall, Sun Tran is a useful tool for anyone using Tucson's public transportation system.