Maps are important...even though you have a smart phone with everything you've ever wanted on it. When flying into a new airport, or needing to pick up a rental car, or wondering how far the international terminal is from the taxi stand, it's good to have a map of the airport.
Download one before you leave home. You can get some direction of which way to go once you get off the plane.You won't even have to wait for your phone to find itself and point the way.
Most airports have great signage. Some do not. Maps come in handy.