TRANSient is a dynamic transit map for the New York City Subway. Train routes change all the time: additional service is added for rush hours while late nights and weekends thin out the system to only the essential routes. The conventional subway map shows this with a complicated service guide and various symbols, but TRANSient makes it simple: the map is updated to show changes in service automatically. Tap the clock icon to explore other dates and times too.
NOTE: I am aware of a map plotting bug on retina devices that cuts off long distances between stations. Sorry for the inconvenience, an update is in the works and will be released as soon as possible.