This is incredible, and even more incredible is that it's taken this long.
Seattle has had a similar app, One Bus Away, for busses, for a long time: http://onebusaway.org.
Seattle has had a similar app, One Bus Away, for busses, for a long time: http://onebusaway.org.
What lets the transit app do this is a that the MTA just enable Wi-Fi and cell signals in all underground stations after a long build-out so that the data can actually be collected system wide from riders using their app.
Glad to hear that cell signal is finally reaching across the subway network - when I was last in NYC it drove me nuts not being able to just browse on my phone whilst waiting for a train.