One of the most frustrating experiences are to scramble through the superstore to find an item that's hiding. more often than not, nobody's there to help you. So you go through your shopping list and then you end up scrambling to find what you had not found yet. Another issue is to find the place where your shopping cart will be cheaper. I'm guessing the latter would not be in the benefit of the grocery store chains...
In any case, here's my ask:
1- Create a shopping list based on recipes I "add", my past shopping habits, how long typically it takes supplies to wear out etc. There are more than a few apps in this space (Link)
2- Tell me where my shopping list would be cheaper (Link)
3- When I go there, guide me through the isles and tell me exactly where each item is. You know where I am (Link). Now mapping all the grocery items is not trivial. It could be done by the store, but as said, they are unlikely to cooperate. You could tag each item with RFID transmitter. Unsure that will work and how many consumer phones exactly have RFID receivers? What you could do is crowd sourcing: Let each customer tag the location and price of each item and collect all the data. Drive sufficient benefits to the crowd, and they'll map it for you.
In return for this service, I'm more than happy to share my historic shopping cart with the grocery store chains, happy to see complete shopping cart coupons etc.
OK, whose on? ;)