Indispensable tour guide!
We lives by this for 4 days in Paris! Everywhere we went we could pull up a map of where we were and get directions to another attraction, hotel, etc. check while you are online first to make sure your hotel is listed (if not its easy to add) then you wont need another map while you are there!
Jennifer Balbach about
Paris Travel Guide (with Offline Maps) - mTrip, v2.0.4