There is an app out called Ibotta. It has been out for Apple products for a while, but has only recently become available for Android users as well.
You download the app to your phone and then have the opportunity to access money back offers- for instance, one of my offers is for a 12 pack of Coke Zero. You do little tasks to increase the monetary value, then scan the item and take a picture of your receipt when you buy it. Bam! I would get $0.75 back if I were to purchase the Coke Zero right now.
It's worth taking a look, it is an excellent way to save money and possibly even get the items for free if you pair a good sale with good coupons!