What to do if your iPhone is lost or stolen
Step 2. The Find My iPhone App
The useful app called Find My iPhone will help you find your missing phone by showing you its location on a map. To use the app, launch it on another iOS device or through iCloud.com on your computer. Once you log in, you will receive a list of devices associated with your account. Select the missing device, and the app will show you where it is on a map. From this point, you have three choices. They are as follows.
1. Play Sound or Send Message. You can use this option to have an alarm go off on your missing iPhone even if it is on silent. In addition, you can send a message to the phone that reads something to the effect of, "This device is lost or stolen." The alarm feature works great if your phone is lost in your own home.
2. Remote Lock. With this option, you can lock your iPhone with a 4-digit passcode if you have not already set one up. Make sure you choose a passcode that you can remember so that you can access your device once you locate it.
3. Remote Wipe. This option erases all of your stored data and returns your iPhone to its factory settings. Use this option carefully and only under extreme circumstances because once you use it, you will no longer be able to track, message, or lock the device.