This is an excellent application. I've played with lots of other metadata tagging applications and they all disappointed me as they do not let me put my metadata where I want to. FastPhotoTagger is the first one I've found that lets me manage my metadata as I want. The fact that it is a GUI for exiftool means that it inherently handles metadata reliably and 'correctly'. The combination of ease of use and configurability make it a 'killer app' for anyone like me who wants to add metadata to their photos without having to constantly wrestle with exiftool.
Genial! I was searching for this kind of tool for a while, but none of the hundreds I've tried was Ok, except FastPhotoTagger !!!