ExifToolGUI is described as 'Graphical user interface to ExifTool for reading and writing metadata in images' and is an app in the photos & graphics category. There are more than 25 alternatives to ExifToolGUI for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and Android. The best alternative is IrfanView. It's not free, so if you're looking for a free alternative, you could try ExifTool or Metadata++. Other great apps like ExifToolGUI are PhotoRex, Exif Pilot, Exif Editor and Better File Attributes.
ExifToolGUI is mainly a Image Viewer but alternatives to it may also be Exif Renamers or Image Editors. Filter by these if you want a narrower list of alternatives or looking for a specific functionality of ExifToolGUI.
MetaImage is the ultimate tool to read, write and edit images metadata. This is first editor that allows you to edit EXIF, IPTC and XMP tags as well as MakerNotes in a beautiful and familiar interface.