Startup Idea : App to tell us Aisle, shelf info in supermarkets

I am sure many of us have encountered this. We would go to a supermarket and we roam through the aisles and waste time because we are not able to find help or know the aisle and shelf or if there are any items remaining for sale in the store. So preloaded tablets would be placed in a few areas in the supermarket and shopper can search for any item and it would tell which aisle, shelf # etc. and how many pieces remaining.