Well its got the map

The only reason I gave it a star is because it has the map, which is the main purpose of it. But:
1) The app just crashes if youre not connected to your network, which is dumb because youre underground for a lot of the time so you dont have it
2) its supposed to tell you where all the trains are real time but theyre usually off by a couple stations

Kasaaan K about DC Metro Map, v3.1