Originally Posted by
TurtleSVS
MTA Bus Time app lets you know where buses are in real time.
"The Transit app" (free) will do the same and it works in any city in the US, Canada, and France. Just hit the app icon and it finds you, the closest transit stops, and with GPS locators on all the buses and trains it will compute the time till each arrives using an algorithm that takes traffic into account. Also can display the schedule, a map of the route you pick with the route highlighted (showing in real time the locations of buses and trains), and in DC will even color the background to match the color of the subway line. Really indispensable for any city dweller/traveler.