They really don’t specify which OS, only that it’s 32 or 64 bit. They want you to use a an r-pi but say to get an OS from the r-pi website which is raspbian by default but at the bottom they list all kinds of other linux distros so I guess I’ll have to just try it out and see what happens. The application is a *.app file if that helps?
https://felenasoft.com/xeoma/en/articles/install-64-32-bit-os-on-raspberry-pi-3/