Saving Changes
When you are satisifed that geo-location information is correct for your images use File -> Save or ⌘S to save the locations. If image backups are not disabled GeoTag will first place a copy of the image file into your backup folder. The program will then invoke ExifTool to update the changed metadata. ExifTool is used because it can update image metadata without affecting the bits that make up the actual image. There is no change to image quality. Also, ExifTool works with most image file formats.
Quitting GeoTag
To exit GeoTag click on the red close button, use ⌘W to close the window, use ⌘Q to quite the application, or use GeoTag -> Quit from the menu. All will do the same thing. There may be a few second delay as GeoTag cleans up before exiting.
Are you sure?
If there are pending changes when you try to end the program GeoTag will confirm that you really intend to discard changes and quit. You can cancel the quit, giving you an opportunity to save changes, or confirm that you really want to quit.