For the course "Current trends in HCI" ("Actuele trends in HCI" in Dutch), I followed at the UHasselt, we had to create something around a theme. This year the theme was "Shopping". Yannick and I wanted to get rid of all the different loyalty cards we had and replace it by a simple alternative that could replace them all.
We created an Android application called LoyaltyWallet. It keeps track of your loyalty cards and allows you to bring just your phone instead of 500 different loyalty cards. You can manage (add and delete), share and use the cards easily. Loyalty cards can also be shared with you, this allows you to share one card with everyone in your dorm without the need to pass a physical card around. When you are in an unknown environment and need to find a store you have a loyalty card of, the app tells you where to go.
Stores can gain crucial insight by asking the user to fill in surveys. By answering the survey, the user gains extra points or discounts. When there are new surveys or pending shares the app notifies you, so you never have to miss a reward or sharing offer.