Doesn

This is a beta at best - first, it does not work on a fully patched SL iMac. It cannot display any of the existing EXIF data. None whatsoever - no GPS, no EXIF, no IPTC, none. No matter whether you try JPG, PNG, PSD, TIF or RAW files - nothing! You can write, though - you dont know what you overwrite, since you cannot see whats there, but yes, you can write. Useless, even although it keeps a backup copy, just in case it messes up.
The tool itself is a GUI for EXIFtool, just in case you are interested. When using the empty Apply suggestion on the developers site, you can see all the metadata in the image, so EXIFtool can read it. But apparently EXIFChanger cannot process the data correctly...
Another nit - it does not remember the last folder you visited. So every time you run the app, you start in "/" and have to navigate your way to the pictures folder in your user folder. Bad software design...

ea6651 about ExifChanger