It's happened to all of us. You dig into your backpack and suddenly your phone isn't there. Panic ensues.
But if you have a tracking app installed on your smartphone, there's no need to worry. Apple and Google each offer apps to help in exactly this scenario: Find My iPhone and Android Device Manager, respectively.
You should have the respective app already installed on your smartphone by default, but if not, you can download the app for your phone in the Apple App Store or Google Play Store.
To turn Find My iPhone on, go to Settings. Scroll down to iCloud, then Find My iPhone and turn it on. On an Android phone, go to Google Settings (or Settings and tap Google), click on Security, then turn on Android Device Manager. You'll want to make sure you have location access turned on as well: go to Settings, then Location and toggle it on.
Both apps will let you track your phone remotely, lock and ring the phone, and wipe your data. Each app also has a website where you can log in to locate and track your devices. If neither is quite your speed, there's also a variety of third-party apps that allow for different features and more functionality.
Have you found a tracking app that works particularly well for you? Comment below and let us know.