QuandoPassa is an Android-based app developed by GH apps, which is a complete and low-cost suite of software and services for optimal use of local public transportation and related services. The app offers a range of features, including real-time tracking of buses on the map, information about bus lines and stops, finding the nearest stops using the phone's GPS, and bus schedules. The suite is based on special optimized algorithms developed in academic environments.

QuandoPassa is an innovative system that allows users to track the movement of buses and calculate the expected arrival times at stops in various ways using their mobile phones. Compared to traditional "smart signs," this system is more modern, cost-effective, and reliable, and it is made in Italy. The app also enables administrators and transport companies to certify completed trips and keep a constant watch on the situation.

Moreover, the app offers advanced services such as route calculation, real-time user alerts, useful information about events, exhibitions, pharmacies, parking locations, tourist attractions, restaurants, integration with other online services such as Google Maps and Bing, publication of data in OpenData format, and online sales of tickets, subscriptions, parking stops, and much more.