• by Mark Walsh  @markfwal, August 31, 2010

CardStar, which makes a smartphone app for storing loyalty cards, has released a free iPad version of the app that is intended to be used at home rather than in retail stores. Unlike the current smartphone app, the iPad one offers coupons from participating merchants including Best Buy, Blockbuster, CVS and PetSmart.

The idea is that the Apple tablet will be used as an electronic coupon-clipper, allowing people to drag and drop offers onto the corresponding retailers' digital loyalty cards inside the iPad app. The device's larger screen will be better suited to duplicate the experience of browsing a Sunday circular than a smartphone.

The saved coupons can then be redeemed at checkout via a customer's original plastic card or through the CardStar smartphone app for the iPhone, BlackBerry and Android. Access to coupons through the smartphone app will not be available until September, starting with the iPhone.

To help avoid information overload, CardStar will only send coupons for retailers stored on a user's card catalog, and allows people to easily see coupons they have previously selected or search for deals from specific brands. Coupons can also be shared via email, and users can check in through Foursquare when at checkout.

CardStar in late July introduced an updated version of its iPhone app that included Foursquare integration as well as the ability to sync loyalty card accounts across multiple devices. Since launching in 2009, CardStar's smartphone app has had 2 million downloads and more than 700,000 active users.

The latest edition of the CardStar iPhone app has received an average rating of three out of five stars in the App Store based on 225 ratings. The biggest complaint, indicated by reviews posted with ratings, centers on the inability to consistently scan the CardStar app successfully at checkout.

One reviewer who gave the app a four-star rating, for example, wrote: "It usually doesn't scan at self-checkout machines but they can use a hand scanner and that usually works. Worst case scenario, you still have your card number and that's still better than carrying the actual cards around." Other reviewers were less forgiving.

Nearly one in five smartphone owners made a special trip to the store after receiving a mobile coupon, according to new research released Tuesday by InsightExpress in Millennial Media's latest monthly metrics report. The survey also found that 45% of mobile users prefer to receive coupons via text message, 28% by finding offers through an app, and 27% by opting in to receive them in stores.