Will downloaded maps remain after I update to the most current version?

All downloaded maps will remain on your device. If there are critical updates on map data, you will be asked to update the map before use. Access to downloaded maps will only be restricted when you downgrade your service.

Please also ensure that you are using the latest version of the app: 

For Android devices: https://play.google.com/store/apps/details?id=com.fatmaprn&hl=en

For Apple iOS devices: https://itunes.apple.com/us/app/fatmap-ski-bike-hike-guide/id1294681561?mt=8