Misleading information spread out this week that Square’s credit card reader won’t work on the newest Apple’s iPhone 4. The device’s metal band/antenna is being interrupted by the metal fitting on the headphone jack. Square is an iPhone app that comes with an attachment to accept real credit card payments.

Square solved the problem by completely redesigning the credit card reader to work with the iPhone 4. Take note of the plastic fitting and not the metal at the base of the headphone jack. They’ve already started shipping the new designs yesterday.

“We’re going to send out a reader automatically to iPhone 4 users if you’ve recently used the app,” Square co-founder Tristan O’Tierney adds on Twitter.

It’s a good move on Square’s part, especially as the app has such a large following on the iPhone.  Being a revolutionary app in the growing mobile industry, Square must ensure compatability with oprating systems and devices.  The two-part consideration is a necessary one, but also doubles the work for Square.  The company is expanding beyond the iPhone as well, with an Android app launched earlier this year.