Geosetter - GeoSetter is a freeware tool for Windows (requires Internet Explorer 10 or higher) for showing and changing geo data and
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
Geotag - GeoTag is a freeware tool for Mac for showing and changing geo data of image files (e.g.
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
Houdahgeo - With HoudahGeo you may "pin" photos to locations where they were taken.
IrfanView - IrfanView ... one of the most popular viewers worldwide.