The company that pioneered the idea of turning any smartphone into a credit card reader is continuing to grow.

Square is doing better than ever, and showing that even in the face of highly mounting competition it can be a major player - the company is processing transactions at a rate of $5 billion per year.

Just a month ago, it was boasting of a rate of $4 billion per year. That's a 25% rate of growth in one month, and it's representative of how the market of mobile payments has exploded in the first half of 2012.

Of course, with that explosion comes an increasing amount of competition. Square's biggest competitor is now PayPal. With PayPal's new mobile credit card reader that can deposit any in-person transaction directly into a user's PayPal account, the differentiation that Square offered has been harshly limited.