Ask HN: What are the most useful iOS apps for those who live in NYC?

I specified NYC because some apps are either local to NYC, or to a small number of cities. I'm mostly just interested in finding useful and well-made apps.

Apps I currently use and love: Foursquare, Overcast, Citymapper, Kayak, Caviar, Instacart, Hotel Tonight, Newton Email, Instapaper.

Any other recommendations? Thanks in advance :)