·Sprint Mobile Br..
You attach a debit card or prepay google wallet and pay with the nfc on the back of your phone. Then it comes out of your bank acct. or wallet balance. Like a mobil speedpass if you are familiar with that. No bill to carrier option.
edit: I used it for about 6 months on my Nexus 4g and really liked it. It also got alot of attention when people notice you paying w your phone.