GeoTag is a free macOS application that allows you to update image metadata with geolocation tags by panning and zooming in a map pane and then clicking on the location where a photo was taken. It is a good way to add location information to photos or fine tune existing location information. Image location can also be set from a GPX track log.
Image file updates are performed using Phil Harvey’s ExifTool. This allows geolocation data to be modified an unlimited number of times without image degradation as ExifTool modifies metadata without changing the image itself.
Download: GeoTag 4.9