Cartwheel is a new 'application' from Target. It's not an application you can download on your phone, tho you can use it on your phone via your phone's browser.
The way Cartwheel works is you sign up using your Facebook account, then you can browse their deals and add them to your cart. For example, yesterday I added a save 20% off graduation cards, save 20% on Father's day cards, and save 15% on Suave hair care products to my cart. Then once you do this, you can either chose to print out the page with the barcode on it to take with you, or you can load this page in your phone's browser. It gives you 1 barcode for all your items in your 'cart'. You can use cartwheel on up to 6 items in the same transaction, the 1 bar code will automatically deduct for all the items. PLUS, you can use cartwheel, with a target coupon and a manufactures coupon on a single item, so you can triple stack it!
Yesterday I used Cartwheel for the first time. I bought 2 suave shampoos (which I also had manufacture coupons for), 2 father's day cards, and a graduation card (amongst a few other things). I gave the cashier my phone to scan first, and she scanned the barcode and it took off $3.68! Then on my receipt it shows in the breakdown what the price was before and after Cartwheel, so it breaks it all down on the receipt for you too! Cartwheel is free to use and another great way to save money, so what are you waiting for?