Oof, I tried searching for "online composition tools," but they all seem to be meant for stitching together panorama photos to produce a larger panorama photo.
Finally I hit on searching for "online gallery image tool" which led me to this one. Good enough!
Haha yeah, this guy doesn't seem too popular here so far. There's definitely a '4-color poster art' effect going on in his work, in which regions of color detail get turned in to lesser blocks of color. The effect and composition looks nice from a distance, but I guess one when zooms in, it can be pretty underwhelming. Of course to be fair, it's video game art, probably not best-evaluated next to classic BD.
Germany's Thomas von Kummant seems to work in a similar style, but arguably does much better detail-work, as seen in the cool post-apoc series Gung-Ho.
Oof, I've posted very little so far about German artists, and feel pretty stupid about that. Surely I can start with this guy or Mawril, who's a real genius IMO.