STM is a free Android application developed by ISR Transit inc. in collaboration with the Société de transport de Montréal. It serves as a comprehensive travel companion for commuters in Montreal. With this app, users can easily access updated bus and metro timetables, fare information, and the fastest travel routes using its trip calculator.

One of the key features of STM is its visual locator that helps users find bus stops and metro stations from their current location. The app also provides information about BIXI and Communauto services, making it easier for users to plan their trips. Additionally, users can receive notifications about any metro service disruptions lasting 20 minutes or more and locate customer service centers. The app is easy to navigate and provides accurate information, making it an essential tool for anyone traveling in Montreal.