Check Ins can only be sent to individual people, not within group chats, and you can only have one active at a time. If you want additional people to know you've arrived at your location ...

Check In lives in iMessage’s new expandable app menu: the little plus sign to the left of the text field. Open the thread with the person or people you want to be alerted when you get home.

Or maybe you worry an unexpected check-in wouldn’t be welcome, as busy as we all tend to be. But new research suggests that casually reaching out to people in our social circles means more than ...