I've added the ability to also save the amiibo game icon as well as it was already being downloaded. See screenshot:
Icon will be saved as amiibo.icon and saved in the same folder as your json files, so you can just upload straight away to the switch without needing to mess about finding and installing icons.
This gui is compatible with this modded amiiswap - (read the readme - old generated json files will cause amiiswap to crash - so create new amiibo files with the attached gui).
by mr.dude.