If you’re concerned that someone is trying to spy on your phone, or want to have photo evidence in the case of theft, we have the solution.
Each of the below Android apps lets you use your device’s front-facing camera to take a picture of someone when they try to unlock your phone. We’ll show you how to use them so you can catch snoopers in the act.
Notes on Lock Screen Picture-Taking Apps
Before you install one of these Android apps to catch potential phone thieves, you should know a couple of points common to all of them.
First, these apps can’t monitor attempts to unlock your device with a fingerprint or face unlock. The Android system does not allow apps to see if a biometric unlock attempt was successful or not. Thus, these apps only work for catching incorrect PINs, passwords, or patterns. We’ve compared the Android lock screen security options if you’re not sure what to use.
Even if you use face or fingerprint as your primary lock screen security method, these apps have value. Biometric security options force you to include a PIN, password, or pattern lock as a fallback method, so someone could still attempt to break in with that.
Be aware that Android only counts an unlock attempt as incorrect if you enter four or more digits, characters, or pattern dots. Thus, these apps will ignore short mistakes.
Finally, one of the new features in Android 12 shows an icon when an app accesses your device’s camera or microphone. While this is a privacy feature that lets you know when apps are sneakily accessing these sensitive areas, it can betray the presence of these lock screen capture apps to an intruder.
A green dot will appear on the lock screen if someone gets your PIN wrong and the app takes a picture. If they manage to guess your PIN, they can tap the green icon to see which app was using your camera. Depending on the app you use, this could let them delete the image taken. The chance of someone randomly guessing your PIN is low, but keep this in mind if you’re on an Android version with this feature.
Understanding Device Administrator Apps
Additionally, these apps all require you to set them as device administrators. This is a special Android permission that gives them several powers, including the ability to monitor lock screen attempts. When you enable this, Android will show a message that doing so allows the app to erase your device after too many wrong attempts. However, this is a generic warning and none of the apps below will ever erase your device.
Each app will prompt you to set it as a device admin when you start using it. If you want to toggle this on your own, head to Settings > Security > Device admin apps (on Android 12, this is under Advanced Settings in Security) and enable or disable your chosen app.
Finally, you must remove the device admin permission from an app before you can uninstall it. Visit the menu mentioned above to do this, or look for the Uninstall prompt in each app that will do it for you.
Depending on your Android version, if you try to uninstall an Android app that’s a device admin, it could fail. In modern versions of Android, you’ll instead see a prompt to deactivate the admin permissions and uninstall together.
Lockwatch is a great overall app for taking pictures of people trying to unlock your phone. It’s a straightforward solution that’s easy to use: just enable it and you’ll get an email when someone tries to break into your phone.
To start using Lockwatch, open the app and enable the Send alert email slider. The app will prompt you to set it as a device administrator, as mentioned above. Make sure you have a current email address in the Emails should be sent to field.
After that, hit Number of unlock attempts and choose to require one, two, or three incorrect attempts before the email sends. It’s not a bad idea to set this to two so you don’t get false positive emails when you mistype your own password. To further cut down on false positives, Lockwatch will not send an email if you enter the correct password within 10 seconds of an error.
When Lockwatch catches someone entering the wrong PIN, the email message will include the photo it took, the GPS location of your phone, and a map of the area. You can hopefully use this to track down your Android device, or at least figure out who’s trying to peek.
Lockwatch keeps its Premium features on a different tab. Paying the one-time fee for Premium lets you get alerts if your device’s SIM card changes, as well as if someone powers off your phone without unlocking it. You can also get three photos instead of one, plus a sound clip, in the email. For a few dollars, this gives you a lot more information.
Download: Lockwatch (Free, premium version available)
2. Third Eye
Third Eye performs a similar function to Lockwatch, but it delivers pictures of the intruder on your phone instead of via email. After installing it, you’ll need to activate it as a device administrator and provide other permissions so it can function properly.
From there, you’ll find a straightforward main menu. Make sure Intruder detection is enabled and the app will take a picture when someone tries to break in. You can set the Number of unlock attempts required for an alert to trigger from one to five. Unlike Lockwatch, Third Eye will take a picture even if you enter the correct passcode within a few seconds.
This app also provides a bit of extra information. The Last Unlock Time field lets you know when your phone was last used (prior to the current session), while the Unlock log provides a timeline of when your phone was unlocked and how long you used it after unlocking. Swipe to the Photo Log tab to see pictures of people who attempted to break in.
Expand the three-dot Menu button at the top-right and choose Settings to tweak a few options related to Third Eye’s notifications. By default, it tells you when your phone was last unlocked every time you open it, which can become annoying. You can also disable the notification about intruders when unlocking your phone and back up captured shots to Google Drive.
While Lockwatch has no ads, Third Eye is loaded with them. You’ll have to put up with frequent full-screen ads inside the app, which are obnoxious. The only in-app purchase the app offers is to remove the ads; you don’t unlock any additional features by paying.
If you don’t like getting intruder pictures via email and would rather have them on your device, Third Eye is a decent option. It’s suitable for people who want to catch friends snooping, but having pictures on your phone won’t help you catch a thief who steals your device. And as mentioned above, if someone got into your phone and saw the green icon on Android 12+, they could find the app and delete the photos, covering their tracks.
Lockwatch also provides you with more information to help track down a stolen phone, like your device’s location. As a result, there’s not much reason to use Third Eye over it.
Download: Third Eye (Free)
Another solid choice for catching phone snoopers, CrookCatcher uses an attractive dark theme with green accents. Like the other choices, its guided setup walks you through setting the app as a device administrator and granting the necessary permissions.
Once you’re through that, you’ll find a simple multi-tab interface. The Home tab lets you deactivate the service and read a bit more about it. On the right, you’ll see the Photos tab that collects pictures of intruders. Each picture comes with a map with your device’s location. Tap the i symbol to see exact coordinates and an estimated address, which you can then open in Google Maps.
Use the Settings tab on the left to adjust options. You can set the Failed unlock threshold anywhere from one to five. Unlike Lockwatch, CrookCatcher will activate even if you enter the right passcode a few seconds after a mistake. Below this, you can choose how many photos to take, as well as enable email and device notifications.
On this page, features that require the Premium upgrade are clearly marked. The Premium version is a one-time purchase that unlocks more options, like recording sound, playing an alarm, displaying a message, taking more photos, and disguising the app in your app drawer.
It also removes the annoying full-screen ads, which are a pain when configuring the app. Like Third Eye, they appear constantly.
Overall, CrookCatcher is a decent free option that’s a lot better if you upgrade. The option to have both email and device alerts is nice, and it provides more info than Third Eye. Consider it if you find the others underwhelming.
Download: CrookCatcher (Free, premium version available)
Did Someone Try to Unlock Your Phone? Discover the Culprit
We’ve looked at a few solid apps that let you take a picture when someone enters the wrong password on your Android phone. They each have slightly different features and use cases.
Lockwatch is a great free option that doesn’t have any annoying ads. Third Eye won’t do much in the case of theft, but will catch prying friends. And CrookCatcher lets you see the photos both in-app and by email, making it a good all-around choice.
Whichever you choose, upgrading to the premium version is only a few dollars, which is well worth the cost if it helps you recover a stolen phone. And don’t forget that taking a photo of someone who tries to unlock your phone is only one way to protect yourself against phone theft.
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