As I needed a list of country flag images named with ISO3, and couldn't find,
I uploaded my version free (see license on bottom).
Above there are two ZIP containing country flags images (PNG format)
sizes of 64x64 and 128x128
of the ~250 countries
as the file name is ISO3 standard
and not two letter (ISO 3166-2) or full name as most flags out there...
license and images are all taken from: