That minuscule subset is well designed, yes, the rest decent BUT some of them with in my opinion predatory pricing in many cases, $9/wk to download some wallpaper or some sleep noises app. But yes, they are not the only ones doing it. If you are interested search on the appstore among the boatload of apps they have.

if you browse Bending Spoons' site on archive.org you'll see that a few years ago they indeed sold wallpaper apps and keyboard apps for debatable prices. They had even more apps, but most of them were removed entirely from their portfolio, and some ended up in the account of Easy Tiger Apps, LLC [1], including a 4,99€/week step counting app that is a blatant rip off of a more famous one

[1]: https://apps.apple.com/tz/developer/easy-tiger-apps-llc/id57...