They could switch to a different mechanism for app stores every month. Force app stores to be rewritten every month to use a procedurally generated new API, developers have to re-apply every month, and users have to go through the laborious setup process every month. And every time, present it with a cheerful message: "To bring a childlike sense of wonder to our customers, today we launch the new improved 3rd party app store API"
They could switch to a different mechanism for app stores every month. Force app stores to be rewritten every month to use a procedurally generated new API, developers have to re-apply every month, and users have to go through the laborious setup process every month. And every time, present it with a cheerful message: "To bring a childlike sense of wonder to our customers, today we launch the new improved 3rd party app store API"