Sprint plan gives you perpetual iPhone upgrades
 

Sprint isn't going to let T-Mobile's iPhone upgrade promo go unanswered. It's launching iPhone Forever, a payment plan that lets you upgrade iPhones at any time without facing an up-front payment or a rate hike. So long as you're willing to shell...

http://www.engadget.com/2015/08/17/s...cid%3Drss_semi