The Reminders app was given a complete overhaul with the release of iOS 13. The all-new design includes new features such as a "quick toolbar," enhanced Siri intelligence and Siri suggestions, the ability to add photos, documents, scans, and web links, and the ability to create tasks and grouped lists.
Tasks and grouped lists makes the Reminders app more useful by allowing you to add smaller tasks to larger groups. Say you wanted to do a little shopping, and you created 3 separate lists for the grocery store, Target and Home Depot. You could drag your 3 lists into one group titled Shopping and have them all in one place. Here's how to create a grouped list in iOS 13 and later: