Square is a mobile payment service that is led by Jack Dorsey, one of the co-founders of Twitter. Square is growing at a rapid pace and they are ending 2012 with a bang. Square is ending 2012 with $341 million in funding and they are processing around $10 billion per year. Square’s mobile card reader is now being used by over 40,000 retailers. However Square’s competition is increasing at a rapid pace. Other mobile credit card readers that entered the market include PayPal Here, Intuit GoPayment Reader, iZettle, and Google Wallet.