intuit-iphone-screenFinancial software maker Intuit is expanding its iPhone portfolio today with the release of its GoPayment application in Apple’s App Store, allowing businesses to process credit card payments on their iPhones or iPod Touches.

Businesses use GoPayment to process credit card transactions (either by entering the credit card number into the phone, or by swiping the card in an optional credit card scanner), print or send receipts, and synchronize that payment data with their accounts in Intuit’s small business software QuickBooks. The Mountain View, Calif. company first released GoPayment back in May, but while it was available as a native downloadable app on the BlackBerry Curve and a few other smartphones, there was no iPhone app. So until today, businesses with iPhones and iPod Touches were stuck using the mobile web site. (Functionally, it sounds like the app and the mobile web site are similar, but in the iPhone world, apps get all the attention. For example, Apple has highlighted competitor Innerfence’s Credit Card Terminal app in its promotional materials.)

Like the other GoPayment apps, the iPhone/iPod version can be downloaded for free — but in order to process payments, you’ll need a GoPayment account, which costs $19.95 a month plus a $59.95 setup fee. Intuit says that for a limited time, it will waive the fee for setup and the first two months.

The company is trying to reach its core consumers via the iPhone too, with the iPhone version of its Quicken Online personal finance site.