Philips have been trialling the technology in some European supermarkets.
You add your shopping list to the app, enter the store and using a complicated system involving the LED lights in the store the app pinpoints your location and give you a suitable route to the ingredients on your list + offers you additional savings and presumably extra ‘discounts’.
The beauty for stores is that they don’t need to add any infrastructure other than change a few lightbulbs and for those new to a store layout it’s easy to find everything… in theory…