We don’t store the receipts because we don’t get receipts. It’s called “Data Privacy.” We don’t know who buys our games on Google, Apple, Steam, or Amazon. The only data about the customers the platforms share with us is countries / zip codes.
The only way for us to get you a copy of the game on Google if you buy it on Apple is for us to go and buy you a copy ourselves. But think about that for a moment: if you spent $6 on a game on Apple, we get $4. Then I pay $1 in royalties to the author. If I then turn around and buy you a copy of the game on Google, I’ve just spent $6 when I made $3. I suppose you could say, well, sure, but then you have another sale! Yes, but then Google takes $2, I get $4, and pay $1 in royalties, leaving me with $3. That means Google got $2, Apple got $2, the author got $2, you got a game on two platforms, and the company received $0. How long do you think we can stay in business if we don’t make any money?
Does that answer your question?