Receipt Hog is a free App that you can get from iTunes for your iPhone. It is currently not available for Android. The App essentially pays you for sending in photos of your grocery receipts which are used for market research. Receipts are sent in anonymously.
As you upload receipts you get points for each one. It does not matter how much you spend, the points are the same. As you upload more receipts the points increase from 10 per receipt in the beginning to up to 25 per receipt. If you are one who shops in frequent small trips this App could really pay off for you.
+Receipthog+App+IPhone You can use Receipt Hog to upload receipts with the camera on your iPhone at any Grocery supercenter, club store, dollar store, drugstore, convenience store, or pet supply store. You can not use it for clothing, specialty stores, department stores or restaurants.
Cash out your coins for Cash or you can donate to charity. 1000 coins gets you $5, 1800 coins is worth $10, 3200 coins gets you $20 and 4500 coins pays $30. Payments are made through PayPal. As you can see, if you save up your points you get more money per coin saved.