We have recently added a feature to allow you to still fly with maptiles even when using Botlink in offline mode. This is very useful for when you'll be flying somewhere in either low or no cellular coverage.
In order to have maptiles while in offline mode you need to download them while you have an internet connection. So before you leave your home or head into the dead zone make sure to open Botlink and press More Options . Select Save Maptiles to download them to your device. A small, orange loading bar will appear on the bottom right of your screen to indicate the progress of the download.
Make sure to be zoomed in fairly far in order to save the maptiles. The app will display a message letting you know if you are still too far out to save the tiles. The good news though is there is no limit to amount of maptiles you can download for offline use (aside from the available space on your device).