Square, the highly publicized credit card reader for iDevices, is now available for sale on Apple’s website and should show up at U.S. Apple Retail Stores later this week. The fact that Apple is promoting the device at its stores should provide a nice bump in sales for a technology that remains in its infancy.

Apple CEO Steve Jobs showcased Square at the recent iPad 2 event, so its placement in Apple stores shouldn’t be all that surprising.

The tiny device, which comes in black or white, works with the free Square app. It allows individuals and businesses to accept credit cards over a 3G or Wi-Fi connection, and works with an iPhone 4, iPad, and the fourth generation iPod touch.

Square Credit Card Reader Now At Apple Stores

Square Credit Card Reader Now At Apple Stores

Although the device itself costs $9.95, new users receive a $10 credit when signing up for a free Square account. Users, who don’t have to sign a contract or incur monthly service fees, are charged 2.75 percent for each transaction.

The Square card accepts America Express, Discover, MasterCard, and Visa card payments.

Once a transaction is complete, the customer receives a receipt via email, while the retailer receives daily deposits in their bank account.

The fact an individual or small retailer can now accept credit cards without signing a long-term contract is a big deal. It will be interesting to see what Apple’s influence will do to grow this type of business.

The free Square app is available in the App Store.