Thank you for your post. Your map collection is stored within the app and is not available to be exported. You can do a full backup of your device using an app called Helium, but you cannot export any of the maps off of your device. We recommend backing up your data (placemarks, lines/tracks) regularly, so please do that before you reset your device. There is information on how to export map features available here: http://help.avenzamaps.com/customer/en/portal/articles/2460172-exporting-map-features-android-
If you run a full backup using Helium, all your map features should be kept with the maps
If you do not back up your device, your imported maps will have to be reimported, and your store maps redownloaded from your Map Store account. You will also have to reimport your map features (placemarks, tracks/lines).
Let me know if you have any other questions!
Avenza Systems Inc