While iOS 13 is rippling for some of its best-known features, especially for system-wide dark mode, the true story may lie in the smaller, unannounced updates. One of these updates is a new reminder setting that marks contacts in a reminder. This will give you a ping command when you send that person an SMS in "messages".
This feature is useful for a variety of reasons. If you have to ask a friend a question later in the day – whatever the risk of forgetting – you can mark your friend in a quick reminder. If you inevitably send your friend a text message about your day or if you open your conversation to read what he has to say, memories will refresh your memory "immediately," Apple notes.
Thanks to Reddit user crsrdtr, we can see the process in action. In iOS 1
This is just one of many new changes to the Reminders app that is just a drop in the ocean compared to the more than 100 new features that iOS 13 has to offer. Apple made sure we had a lot to discover iPhone users with this year's update, and it will not disappoint us Peterson / Gadget Hacks