Starting in March 2020, universal app purchases are coming to iOS and macOS. Apps bought on one platform will be unlocked on the other.
An issue I see with this is pricing. People are used to cheap iOS apps, but if you applied the same pricing to macOS apps, that would be bad for developers. Would the price of universal apps fall somewhere in the middle? Or would everything be a subscription? Apple clearly wants the latter, but no one wants a bunch of subscriptions either.
By 2021, developers will be able to merge iPhone, iPad, and Mac applications into one app or what is known as a “single binary.” This means developers won’t have to submit their work to different Apple App Stores, allowing iOS apps to be downloaded directly from Mac computers — effectively combining the stores.