I just got an idea for a great shopping experience. An app on my phone that I can add my groceries list to and it will tell me where in the shop the particular

I just got an idea for a great shopping experience. An app on my phone that I can add my groceries list to and it will tell me where in the shop the particular item is located and will automatically keep the tally of what I've put in my cart so far so that I know how much I'm spending and my total shopping time will be much smaller. It could also automatically connect to some cart sensor so that I don't even need to scan each item at the cashier, but I can just pay. Something like Amazon Go, but works.