The CASAN app is a free Android application designed to enhance communication between the Companhia Catarinense de Águas e Saneamento and its users. This tool allows residents to access essential services and information directly from their mobile devices, promoting active citizenship. Users can easily view their consumption units' details, including outstanding bills, historical billing data, and water usage statistics, supported with comparative graphs. Additionally, important documents like duplicate bills and debt clearance certificates can be downloaded in PDF format.

The application also features a map interface that helps users locate the nearest CASAN agency based on their current position. Users can report issues such as leaks or water shortages, complete with the option to add photos and geolocation. Furthermore, the app provides personalized notifications about water service interruptions, new bill availability, and alerts for high consumption, ensuring users stay informed even when the app is not actively in use.