Not hard using PHP image-generating functions. I was going to made something like this but I abandoned the idea 'cuz my schoolwork is so heavy
Yeah it's pretty basic stuff if you know that kind of coding, but what impressed me was how polished it is.
I was going to start a thread asking a deck image builder that was:
A) Simple
B) Produces an identical image of what we seen in game
Planplan achieved just that.
I'm willing to bet that 9 out of 10 coders would have
failed in one of those, most likely in both. Keeping things simple and attention in detail are not easy.