Maybe I don't understand your idea correctly. But if you were, for example, willing to give me $1,000 for whatever amount of Bitcoin that I would zap you, how would I be assured that I would get the $1,000? Or if you paid me the $1,000 first, then how would you be assured that I am going to zap you? 

 I mean that you can literally purchase sats in the app and pay with Apple Pay (max 10€ a day). But it’s super expensive (I realized it after I posted this haha) 

 Gotcha, I misunderstood 👍