All three of these apps work on iOS and Android, as well as via Web browsers. Square Cash originally launched using a system that involved sending an email to someone with the dollar amount in the subject line and “Cash@square.com” copied in the message, but the majority of people now use the Square Cash app, which doesn’t involve email. None of these apps requires NFC (near field communication) technology in your phone; all you need is a connection to the Internet. It took me just a few minutes to set up each app, entering details like my debit card number, ZIP code, full name and phone number for verification.

http://recode.net/2015/06/24/everything-you-need-to-know-about-paypal-square-cash-and-venmo/