I just got the app Receipt Hog installed on my phone to earn coins for purchases I make. You simply take a photo of the receipt and they give you coins based on what you spend. At 1000 coins you can redeem for Paypal cash or other gift incentives. I also disordered that this app is a great way to keep track of spending because you can look at your receipt transaction history. I installed the app yesterday and have already captured 3 receipts and was able to see how much I spent in a day. It is counter intuitive in a way, but now I am much more aware of my spending and so I can think twice before making a purchase.
I installed the app a few months ago but have never really played around with it yet, maybe I should start! Is it just certain stores that you capture receipts for, or just about anything? I wonder what they do with all the data, are they just trying to figure out spending habits?