Itch.io is, I think, the only storefront I've ever used that's happy to let you pay for something more than once. It's nice that we can support creators by buying multiple times, but it's really confusing, since I often forget if I've already bought something. It'd be great if the buy button were replaced with a download one, plus an explicit 'pay again' button for extra purchases.

Even worse: when you go to a devlog, there is a buy button and no indication whatsoever that you already bought it.  At least the actual game pages have the download links at the top if you already bought it; the devlog pages have no such thing.