Hoy no Circulas is a free Android application developed by Saúl Pilatowsky, which serves as a simple reminder of the days when your car cannot circulate in the "Hoy no Circula" program in Mexico City and the State of Mexico. The app automatically works with a widget and includes a calendar with reminders for verification months, as well as optional notifications so you never forget when you can't drive.

The app is straightforward and user-friendly, making it easy to set up and use. The widget displays the current day's restriction, and the calendar shows the restrictions for the entire month. The app also allows you to customize notifications and add multiple vehicles, making it an excellent tool for car owners in Mexico City and the State of Mexico.