PhotoQt is now available as AppImage! This link always points to the most recent AppImage: PhotoQt-x86_64.AppImage.

Once downloaded, use a terminal to mark the file as executable:

$ chmod +x ./PhotoQt-x86_64.AppImage

Now everything is ready. Execute the file either from your favorite file manager or directly from the command line:

$ ./PhotoQt-x86_64.AppImage

A big Thank You to probonopd for creating the necessary configuration file!