A single storefront for all platforms in all regions is likely impossible. But a single registry of purchases would work. Dare I say it, a block chain would eve

A single storefront for all platforms in all regions is likely impossible. But a single registry of purchases would work. Dare I say it, a block chain would even be a good implementation. Store fronts take money and pass it on to the developers, registering the ownership. Then the platform allows installation if the software is available and ownership can be confirmed. All without needing a central database or a bazillion remote APIs to query for every store or publisher.