What do you expect Apple to do?

These things are made open source under a permissive license. The whole point is that people can do what they want with the code.

I was actually talking about clones of closed-source applications.

Given that you were replying to a comment specifically about open source, that wasn't clear. Also if an app is closed source, you have to wonder how the cloner obtained the source in order to re-skin it? Is that sort of industrial espionage, or code decompilation of iOS apps common?

You also have to wonder how Apple would know? There are almost half a million apps on the App Store, detailed code analysis of the app binary and comparison with other compiled app binaries on the store is hard enough on an individual basis, and trivially defeated by code obscuration, let alone at app store scale.

What are you suggesting Apple, Google, Microsoft, Amazon and other store operators should be doing?

A permissive license is the only one iOS apps can be released under. GPL and the App Store don't go well together (see https://www.fsf.org/news/2010-05-app-store-compliance)

Not sure what your point is here. Seems to me that even if the FSF was happy with the app store, trivial forks and clones of OSS would reach the app store all the same, no?

That is not an answer to my question.