Needs service to work?!?

Went to Mount Rainer park the other day, thought "Ill use that national park app I got", but no. Many of the features require phone service to work, particularly the maps to find where to go. Youd think that Nat. Geo. could include a built in map, but apparently not. Inside the park, theres basically no service, so the app was useless.

Gregor Harrison about National Parks by National Geographic