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Check In being sent via iMessage while showing notification through the Dynamic Island
When activated, Check In will automatically notify a friend that your iPhone has arrived, and you can choose what details they can see if you don’t complete your Check In. Similarly, if a friend sends you a Check In but their iPhone hasn’t arrived as expected, you can view their location, battery percentage, cellular signal, and more.
However, the feature also has other uses, such as a timer to notify a loved one of your safety when meeting someone new. You can also use it to inform a recipient of your arrival without using ETA in Maps if you already know the route.
Go Here to Read this Fast! How to use Check In for home, different locations, and with timers
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How to use Check In for home, different locations, and with timers
