I had very bad experiences with blockchain-powered apps in the Apple ecosystem (I did try to publish one, which was keep being rejected - managed to get to the level I got on the phone with a real person from the AppStore review team, to no avail). Apart from a handful of wallets, pretty much nothing goes through. It's because the 30% cut that Apple currently takes from every in-app purchase. If an app uses blockhain as a mean of payment, they're passed on and they don't seem to like that very much.