Transfering your Licensed BackCountry Navigator to another device

This guide from Android Market Help Articles will help you to retrieve your
purchased BackCountry Navigator or transfer it to another device:

The same instructions generally apply if you rest or rebuild your device. 

http://www.google.com/support/androidmarket/bin/answer.py?hl=en&answer=113410&topic=1100168

Be aware that if you factory reset your phone, you will have to reinstall all apps.