If you misplace your phone, the Find my phone function will make your phone ring or vibrate so you can easily find it. To use this feature, ensure your phone and watch are within range of each other (10m).
To enable this function
Press the find my phone app icon in the watch shortcuts or in the main menu page, and click on the screen to enable it.
Press once on the icon Search my phone to activate the search. Your smartphone will vibrate or ring when it is close to your watch. Once you locate your device, click the find my phone icon again to turn off the search.