Lister 2 for iPhone lets you create shopping and grocery lists not only easily, but in a way that makes sorting them and finding what you're looking for simple. With support for Dropbox syncing, sharing, password protection, and more, it's a nice option if you want more control over your lists than what the native Reminders app gives you.
With Lister 2 you can create as many lists as you want and choose between general to-do lists or shopping lists. For shopping lists you can drill down to the type of item you need and add a cost to it. Doing this gives you a quick look at the total for your current grocery list.
If you want to password protect lists, you can do so on an individual basis which means not all your lists have to be password protected. You can even create separate passwords for each list if you want.
For lists that need to be shared with others whether for collaboration on a project or sharing a grocery list with a spouse or roommate, you can utilize the built-in Dropbox support to do so.
Lister 2 is a great option for people who want to organize shopping lists into sections with ease or want more options when it comes to to-do's than what the native Reminders app gives you.