Nothing particularly useful - yet.
All this app gives you (at best) is an image of a map. You could find these at nps.gov easily enough.
What this app should be is a faster way to provide the information that's on the National Park Service website already.
Information like: Hours, Directions, Tour times, etc. would be good to have. Links to sites, Google map locations, etc. would make it more interactive and useful. Good start for a free app, but not very compelling.