1.8 is the latest increment in the minor version number. A small change in the numbering, a big change in the dashboard: It is a virtual grid with 5x15 now and you can fling to move the visible window over it. Place widgets anywhere you like as you have more space then widgets in the current version.
Another reason for this update is that still users have problems that were running GPS Essentials 1.4 or older versions. Some background info: Android silently changed the user id for GPS Essentials and with the new user id, the app cannot access the old data. The only workaround is to uninstall GPS Essentials and reinstall it.
In contrary to the theories of some commenters on Android Market, this has nothing to do with ads showing up on the main menu.
While 1.8 is in maintenance mode, progress on 2.0 is ongoing. The next big feature I am currently working on is tracking. There will also be minor improvements like the marker type in your exports.