T-Mobile USA has become the first mobile operator to offer Square payment readers to its customers, allowing smartphone owners on its networks to buy the payment accessory direct from its stores from today.

Square’s attachments are already on sale in Apple Stores and other retailers including Best Buy and Target, allowing iPhone, iPad and Android device owners to process credit card transactions on their mobile device.

The device is being aimed at small business owners that want to offer credit card payments to their customers. The company has set up a dedicated page on its website, here.

Square founder and Twitter co-founder Jack Dorsey announced via Twitter in December that the service now serves over 1 million merchants who are signed up and ready to process transactions.

As a counterpoint, Dorsey said that there are only 8 million merchants who accept credit cards in the US, giving Square a solid chunk of that market. Taking into account the figures that the Twitter co-founder shared, Square had managed to expand and capture 1/8th of the entire credit card processing market in just 2 short years since its launch.

Square is currently on the lookout for the best talent in software engineering, hardware engineering, creative, communications and public relations, compliance, finance, legal, marketing, and risk. With $168M in funding, the company can definitely afford to hire all of these positions and so created a slick new recruitment video to help it do so.