I used the app this weekend and while very basic, it is very useful and the open API will be a valuable resource to anyone looking to build a transit/travel app.
Get the app here https://itunes.apple.com/us/app/id561507659?mt=8
The API is here http://datamine.mta.info/ I have yet to play with it, but from what I remember it was pretty straight forward.
Anyone going to use the data feed for something else beside finding your next train?
I’d love to hear about it.