T-Mobile keeps gaining steam on ‘uncarrier’ plans, iPhone launch BGR Contributor October 01, 2013 12:50 PM ET Font Size: Evidence keeps piling up that American consumers really do want an alternative to traditional wireless carriers. A new report from Kantar Worldpanel shows that T-Mobile’s share of American carrier smartphone sales grew to its highest in a year during the quarter ending on August 2013. In all, T-Mobile sold just over 13% of all smartphones between June and August this year, an increase of 1.1 percentage points from the previous quarter. Kantar says that the carrier has benefited from finally getting to sell Apple’s popular iPhone to its customers and from its “uncarrier” plans that offer popular smartphones such as the Galaxy S4 and the HTC One for little to no money down. T-Mobile in August posted a quarterly net addition in postpaid subscribers for the first time in four years so it seems that the company has continued to build its momentum all summer.