Yes, the official and essential app for Swiss trains is SBB Mobile. It is widely considered one of the best transit apps in the world due to its incredible accuracy and integration. The app allows you to see real-time timetables for all Swiss public transport, including trains, buses, trams, boats, and even mountain cable cars. One of its most popular features is EasyRide: you simply "slide to check-in" when you board and "slide to check-out" when you arrive, and the app automatically calculates the cheapest possible fare for your journey at the end of the day. You can also purchase "Supersaver" tickets (which offer deep discounts for specific off-peak trains) directly through the app. The app provides detailed platform information, live train formations (showing which cars are less crowded), and push notifications for any delays or track changes. It is available for both iOS and Android and supports English, French, German, and Italian. For any tourist visiting Switzerland, this app is indispensable for navigating the country's dense and punctual rail network.