By Marina Lopes WASHINGTON (Reuters) – T-Mobile US Inc said on Wednesday its offering at least a million cellphone users the chance to use an Apple Inc iPhone in a free one-week trial of the No. 4 U.S. wireless carriers network with unlimited access. The announcement is the latest promotion from T-Mobile, which last year shook up the industry by unbundling service fees from device costs, a move other carriers soon followed. We believe every Verizon, and every ATT customer should cheat on their carrier and enjoy every minute of it, said T-Mobile CEO John Legere, speaking at a T-Mobile event in Seattle that was broadcast on the Internet. T-Mobiles aggressive discounting won it more subscribers in the first quarter of 2014 than any of the top wireless carriers combined.