An iPhone can be set up to remind users of helpful details whenever they message a specific person in their Apple Contacts. This is potentially much more useful than a general list of reminders or even a reminder that sends a notification on a date and time, as is usually the case.
Apple includes a complete set of utility apps on the iPhone, making it immediately valuable for new users even if it's their first Apple device and there aren't any third-party apps installed yet. Email, the App Store, and the Safari browser are well known, and something equivalent can be found on any mobile device. More unusual utility apps include Measure, Compass, Magnifier, and more to extend the iPhone's usefulness further. The Reminders app is also a utility app but is packed with so many features that it can quickly become an app that's used daily.
A little-known but handy iPhone feature allows people to set a reminder for themselves when messaging a particular person. This option is found in Apple’s Reminders app. After creating a new reminder, the user can tap the circled letter 'i' button to see more options. After switching on the 'When Messaging' toggle, a button appears to 'Choose Person.' Tapping this opens a list of contacts to pick from. When the contact is messaged next, users will receive a notification with the contents of the reminder. This is a great way to remember important details and fun stories to share. It works for both iMessages and SMS texts, so iPhone owners can receive reminders when chatting with Android users as well as those using Apple devices.
How To Add An iPhone Contact For Reminders
When selecting a person to get a reminder when messaging, it has to be someone on the iPhone's Contacts list. Users can use the search box at the top to find a name quickly or scroll to find the contact. If not found, tap the Groups button to check if they are in a different contact group. If the person simply isn't in Contacts yet, they'll need to be added to send a message and set up a reminder on the iPhone.
Unfortunately, Apple doesn't provide a way to create a new contact from the Messages or Reminders app. It's easy to do with the Contacts app, however. After opening the Contacts app, tap the plus button and fill in the person's name. A phone number or email address is needed to use the Messages app, with an email address working if the person has an Apple ID tied to that email. Once the contact is saved, users can create a reminder for the next time the person is messaged from the iPhone.
Source: Apple