A shopping app that adapts to your behaviour
Most shopping apps are a list of text. They typically contain some aids for easily writing gherkin, and cantaloupe and how many but they are still a list from top to bottom.
Most grocery stores have vegetables in a part of the store so when you pick the tomatoes you probably want the corn and the apples at the same time; but not the milk, chocolate or spices.
So I suggest the list reorders itself when you start picking to show what’s nearby.
One can also use the localisation features of the phone to find out which store you are in and adapt even more as it then can know whether bread is in the start of the store or later.