The tool is free and the sourcecode is totaly visible, also open source, except exiftool. Because for that, the tool is completelly modificable and expandable. It can use online or download it and use it local.
The tool is also a EXIF GPS photo viewer.
PS: many peoples use the tool GeoSetter. I have use the geosetter for many years. The problem is, that geosetter use Internet Explorer (deprecated). The other thing is, that geosetter use a map in the Internet Explorer. The difference to my tool is, that geosetter can read and write files directly on a computer. For security reasons, browser like Firefox and Chrome cannot directly access the data in the computer. All other functions are also possible with my tool, like GPX route data comparison with photos - when you can code it or know someone who will do it.
Please read the Info-Page!