Cardback is an Indian startup that intends to help debit and credit card users in India identify their best card for every payment they make, and see how much they will save from using that card.
The official Cardback app has recently landed on the Windows Phone Store. All you need to do is indicate how much you're paying, and where. Cardback will save you the trouble of doing complicated calculations and checking out promotions before every payment. This is based on several factors, including how you earn and redeem reward points on your cards, and any running special offers.