With the application Metro New York, you have access to the map of New Yorks subway.
You can search stations directly on the map or in a list sorted by name, by line or by proximity of your position with the GPS.
Metro New York allows you to calculate the shortest path between two stations : you select a start station and a finish station and the application will show you : the path between the stations, the number of connections and the steps of your path.
You can see a station on the city map without exiting the application.