Earlier this month a Sat Nav app was made available for U.K. BlackBerry users via the BlackBerry Beta Zone in the form of the BlackBerry Navigator app. It supported a handful of BlackBerry 7 devices and now more devices have been added to the roster.
When you log into BlackBerry Beta Zone be sure to check you have selected for the correct device. It should also be noted that there seems to be three different version numbers going around but none of them have differences between them.
If you don't yet have a BlackBerry Beta Zone account, it is fast and easy to sign up, all you need is your BlackBerry ID.