I'm a sucker for a really well-made iOS grocery app. One smart enough to arrange my shopping list in the order I pick up items at the store. And one that can live on my Apple Watch, so I don't have to juggle my phone along with my shopping cart.
Until recently, my go-to grocery app was Capitan (free). (The App Store title is “Grocery Shopping List by Capitan.”) It arranges items under standard supermarket categories--fruits, vegetables, dairy & eggs, etc.--which you can easily customize and reorder to suit your own store's layout. If you typically buy the same items week to week, Capitan offers a handy menu of previous purchases to make compiling your next list easy. As you shop with your Watch, a touch will add a strikethrough to each item on Capitan's list.
It's the perfect grocery-shopping app, except for one thing: Capitan does not integrate with Apple's Reminders app.
For me, that's a real drawback. I like being able to tell Siri to add items to my grocery list throughout the week. Those items end up in Reminders. If those Reminders items are then going to appear in Capitan, I have to add them manually. (Of course, the Reminders app itself is not yet available on the Watch.)
Then I was reminded about Grocery (free; $2.99 to remove ads). (The full App Store name is "Grocery - Smart Grocery List" by Conrad Stoll.) While it does not have Capitan's categories or pleasant color scheme, it offers several benefits Capitan lacks.
Grocery lets you pre-order your list before heading to the store. But once you're there, it pays attention to the order in which you check off items from the list. That's the order it remembers the next time you create a list that includes past purchases. (Capitan only remembers the order of your categories, not the specific items in those categories.) And Grocery allows you to have multiple stores and multiple lists saved, should you happen to shop at different locations with different layouts. (Nothing says they even have to be supermarkets.)
Best of all, Grocery integrates seamlessly with Siri, via Reminders. Add anything to a grocery list in Reminders, and it will automatically show up in the Grocery app. Select an item as purchased in Grocery (which, instead of striking through it, makes it vanish from the list) and it will be removed from Reminders.
Neither of these apps is well known or typically included on the many "best grocery apps" lists you'll see. They can even be tough to find in the App Store. But if your needs are anything like mine, they'll be worth seeking out. For me, they're the cream of the crop when it comes to grocery-shopping convenience and utility.