For example, perhaps the local store employee saw nothing but the store has a security camera. Is the owner of the footage required by law to hand over the recording without any type of warrant?
Yes. There is no "reasonable expectation of privacy" in a store open to the public, so no warrant is necessary.
The same thing may be relevant here, called the "third party doctrine". You told a third party, Apple, that you wanted the app. Because Apple is a third party, there is no reasonable expectation of privacy, and therefore no search warrant is necessary.