Startup Idea : Grocery Store item finder

you tell your 'grocery list' which store you're shopping, and the app tells your list which aisle each thing is in. then instead of 'crossing' the item off your list, the check-off button would be a confirmation that item was found in that aisle. you'd get a sort of 'crowdsourced' map of the store. if the grocery store moves things around, then when you find the item in a different aisle, you 'update' that entry. this would help people shopping in unfamiliar stores, and would help anyone get all their items more efficiently (instead of crossing back and forth across the store)