I actually installed this app last week and have already received money back. Savings Catcher from Walmart compares prices from top stores in your area. If it finds a lower ad price on eligible items - like groceries and everyday supplies for your family.
AWESOME IDEA: Put one dollar in a jar every time you complete a workout. When you achieve your goal 20 lbs. lost, etc.) use the money to treat yourself! a massage, a cute pair of jeans, whatever feels in line with what you've accomplished. Most excellent!