Device-to-device audio communication (think QR codes, but made out of sound) seems very underrated. Much better UX than QR codes or NFC because you don't have to worry about putting your phone in the exactly right place or pointing it in the right direction.

Anyone here with more detailed takes on this?

would love to try it.

NFC works amazingly in apple pay--smoothest, fastest experience i've ever had transacting.

unfortunately not possible for in-app P2P transactions due to apple restrictions. NFC uses "device" (tapper) & "card" mode (tapped). Android can do both, iPhone apps are only allowed do the former.