Here’s how Square Cash works. Say you want to send $47.12 to your sister. You just compose an email with her email address in the “To” field and, in the “CC” field, you enter “firstname.lastname@example.org.” In the subject field, you enter the amount you’re sending — in this case, “$47.12.” You can leave the message body blank, or add a note explaining you’re sending the money and why. Then, you just press Send.
This sounds like magic.