While it is rare, some people report that they are stuck at the welcome screen of BackCountry Navigator.
Almost always, this is traced back to "aggressive" task management settings.
(In other cases, they never get back to me or simply leave a comment in the Market about this problem, so I don't know)
Today I downloaded the free Spare Parts app. Its one of a gazillion apps that allows you to modify secret system settings. .
Under "Other secret system settings" it has an Activity Process Management setting.
If you set this to agressive, ignoring a stern warning, you will find that BackCountry Navigator will not open properly.
Change it back to Normal and it will work.
Agressive is a bad task policy that will cause you lots of problems with this and other apps. Supposedly it kills activities when they are no longer needed, but it makes some stupid decisions about what "no longer needed" means.
Note: another app, or even your devices defaults may have set this policy to aggressive with or without your knowledge. It's worth checking.