Since it's all on your phone, you can send your friends gift cards if you aren't going to use them, and track all your receipts. SWYP also has some other compelling options, such as "Restaurant Mode," which locks the device into one card, so the server doesn't have access to your entire wallet.
It's dropping in the fall, but you can pre-order it now for $49.
Ethan Wolff-Mann is an editor at Supercompressor. He only uses gold coins. Follow him on Instagram.