VeriFone, one of the biggest payment processing systems worldwide, has just announced Sail, its own mobile card reader. The system, which will launch this summer, works with either an iOS or Android app; the app will include barcode scanning and a system for integrating external tools like loyalty programs. As you may have realized, Sail isn't all that different from Square's own system, which has been operating successfully for a year and recently began showing up in NYC taxis.

Previously, VeriFone has been sharply critical of Square, going so far as to write a program highlighting security problems with its hardware. As Business Insider outlined yesterday, VeriFone now hopes to compete by leveraging its substantial payment processing network. Larger businesses can pay $9.95 per month for a lower transaction rate of 1.95 percent (instead of the standard 2.70 percent), and companies will be given the option to upgrade to VeriFone's other products as they grow. It's also offering the underlying platform to third-party developers, so other apps can use the dongle as long as they send payment through VeriFone. The company has a ways to go to catch up to Square, but with — as VeriFone claims — 65 percent of physical retail transactions in the US passing through its service, it will have a substantial head start.