NYCMate (NYC Bus & Subway) Everything you need to master the NYC bus and subway - for free! It works offline, and has info for all routes... except that some of them (late night schedules, for instance) are wrong. Use with care - but still the most comprehensive app for NYC transit info.
New York City Walks This $4.99 app contains 10 GPS-guided walking tours around New York City. A great way to really see the city in detail.
Time Out New York Time Out is the best resource to let you know what's going on in music, theatre, dance, nightlife, anything you can think of and more. Great for figuring out how to make the most out of your visit by checking out local culture.
tkts This free app is the best way to get all the listings of Broadway and Off-Broadway shows that are sold at the TKTS discount booths - which is where most New Yorkers get their show tickets. A good app for those looking to see a live show at a discount.
Museums In NYC Some of the greatest museums in the United States and even the world are located in New York City. This app lists and maps them all - and contains info and hours for them as well as information on events. It would be nice if more detailed descriptions of the museums were listed under their info.