For iOS: Tap Settings, iCloud, Find My iPhone (or iPad), and make sure the Find My iPhone setting is enabled. Then sign into iCloud.com on a desktop web browser, click the Find My iPhone icon, and see for yourself whether your devices pop up on the map.
2. Set your device to require a passcode immediately (or almost immediately) after putting it to sleep [Android and iOS]
If you like, you can set your iPhone or Android phone to wake without a passcode after it's recently been unlocked — say, within a few hours or just a few minutes.
Convenient, yes, but wise? Hmmm. For a tablet that usually sits at home, letting it wake without a passcode within an hour or so of being unlocked is probably OK.
For the phone in your pocket, though, five minutes or less without needing a passcode is a smart move. Personally, though, I don't allow any of my iOS or Android phones to unlock without a passcode, ever.
Here's how to see — and perhaps strengthen — your own "wake without passcode" settings.
For Android: Tap Settings > Security > Automatically lock, then pick a setting: anywhere from 30 minutes to immediately. Among the choices: 30 seconds or even just five seconds, a nice compromise between convenience and security.
For iOS: Tap Settings > Passcode > Require Passcode, then make your choice, from immediately to four hours. Note: if you're using Touch ID to unlock your iPhone or iPad, "Immediately" is the only "Require Passcode" setting that appears.
3. Block access to Control Center [iOS]
Starting with iOS 7, both iPhones and iPads have shipped with Control Center, a handy slide-up window that gives you quick access to your device's Wi-Fi and cellular settings, media controls, alarms and timers, and the camera.
Because you can access it from the lock screen, Control Center makes it easy to put your iPhone into "Do Not Disturb" mode without entering a passcode, or switch on "Airplane mode" before your flight takes off.
Unfortunately, Control Center also makes it easy for anyone to mess with your iPhone's or iPad's camera, alarm clock or wireless settings — even allowing, say, a thief to put your stolen iPhone into airplane mode, rendering the Find My iPhone app useless.
My recommendation: Block access to Control Center from your iDevice's lock screen. No, you won't be able to flip on "Do Not Disturb" with a flick and a tap anymore, but better safe than sorry.
Tap Settings > Control Center, then switch off the "Access on Lock Screen" setting.
4. Use a stronger PIN, or a straight-up password [Android and iOS]
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