Entertainment Apps

Open Table
Online restaurant reservations

Urban Spoon
Restaurant reviews and recommendations (crowd sourced), links to Open Table for reservations.  Fun "shake" option for a random suggestion based on location, price and cuisine.
Yelp Restaurant reviews and information (crowd sourced)
Flixster Movie theater locations/showtimes and Rotten Tomato Reviews
Fandango Movie theater locations/showtimes and ticket purchase
IMDb Showtimes, detailed movie information, also TV and celebrities information

DC Going Out Guide

Washington Post's Going Out Guide for events, museums and activities in the DC area

Smithsonian What's going on at all of the Smithsonian museums
Discount tickets to performances
Stubhub Ticket resale site - buy or sell tickets to performances and athletic events
Broadway Box
Discounted tickets to Broadway and Off-Broadway shows
Find My Tap
Find your favorite beer at a nearby bar, or find a good local bar