T-Mobile US is seeing an uptick in customers and revenue, after revealing its new UnCarrier plans earlier this year. Specifically, the fourth-largest carrier in the US said it added 1.1 million customers during fiscal Q2, 678,000 of which were for the primary T-Mobile and MetroPCS brands. This is T-Mobile's strongest growth in four years, perhaps indicating its UnCarrier movement is going in the right direction. 

"T-Mobile's UnCarrier approach has clearly resonated with consumers," said John Legere, president & CEO of T-Mobile. "By fixing the things that drive them mad, like contracts and upgrades, and freeing them from the two-year sentences imposed on them by our competitors, they are choosing the new T-Mobile in unprecedented numbers."

Overall, 4.3 million smartphones were sold on the carrier during the quarter. While T-Mobile says it wasn't solely due to the iPhone, Apple's device did make up 29 per cent of handset sales on the network. Other smartphones, including the Samsung Galaxy S4, helped boost sales, according to T-Mobile. Total smartphone sales accounted for 86 per cent of phone units sold, up from 71 per cent in the same quarter last year. 

Read: T-Mobile USA reveals 'Jump' - a semiannual upgrade program for phones, launches 14 July

T-Mobile also announced that its 4G LTE network has been rolled out in 116 metro markets across the US, covering 157 million people in total. The fast growth can be attributed to its acquisition of MetroPCS, and in time, its latest acquisition of US Cellular might also prove a huge benefit. Revenues for Q2 were at $6.3 billion, up from $4.4 billion in the same quarter last year. However, net income was down from $207 million to a loss of $16 million

Legere and Co have been aggressive with their new UnCarrier approach. Under the UnCarrier plan customers do not have to sign a two-year contract, but instead pay full price for a handset at time of purchase or $149 (£65) up front with $20 a month in payments for the next 24 months. Using the iPhone 5 as an example, that will round out to $619 over two years, or $20 cheaper than Apple's unlocked version. Once the payment period is up, the phone is unlocked and yours to take to any carrier.