It learns the shop, you don't teach it
No aisle numbers to type in, no store layouts to pick from. Adding a shop is typing its name. The learning is a by-product of shopping you were doing anyway.
Ready on the first trip
A new list arrives with several hundred everyday products already sorted into categories, so it is in a sensible order before the app has learned anything at all.
Several shops, one view
Each shop keeps its own list and its own layout, and the home screen tells you what is waiting where. Standing in one shop, the things you need elsewhere are grouped by the aisle you are standing in.
One list, two phones. Either of you adds things during the week, and ticking something off in the shop shows up on the other phone straight away. No more two loaves of bread.
Send it to whoever is going
You can share a read-only link to one shop's list, for when somebody is passing anyway. It opens in any browser with nothing to install.
Free, and quiet about you
No account, no email address, no password, no adverts. Your list stays on your phone unless you deliberately share it. If you allow location it is read once at the start of a shop, to tell which shop you are in, and it never leaves the device. It works with no signal, which matters more in a supermarket than most places.