Sale has ended but you can still get this app.
Download Offline BRP Tour Map(s) Now

Official Description

Know where you are while visiting the blue ridge parkway by tracking yourself on the offline tour map and offline map even when your phone/pad is offline which is often the case in BRP montain regions (It's a good practice to start the app where the internet is available). The tour map offers more detailed information than the map comes with the device. The offline maps bring you a peace of mind when you know where you are when internet is not available and you are in/outside the BRP park! Upcoming versions will offer points of interest.

You can do a lot more with the app such as share your trip as a named trail with friends, displaying your friends location, etc.

The large app file size is due to the embedded offline tiles that you don't have to download yourself.