Paying for your coffee with your smartphone is so old-school. So, like, 2010. Today, PayPal is working on paying with wearable devices like activity trackers, smartwatches, or possibly even smart specs like Google Glass. That’s in the future, though.

http://venturebeat.com/2014/04/07/paypal-cto-on-payments-the-uber-experience-and-paying-with-fitbit-interview/