How Secure Is the App Locker For Android?

If you do a quick search of the phrase “app lock” in Google Play Store, you will find plenty of apps, both free and paid, that allow you to lock individual app and prevent unauthorized access. In Make Tech Easier, I have even recommended a few app-locker, including ZDBox, Seal and Widget Locker. The question is, how reliable are these apps? Can you depend on them to protect your phone?

How the App Locker works?

After you have installed the app locker, you will be able to choose which apps you want to protect and the unlock mode (password, pin or pattern). What the app does is to continuously monitor the running apps and see which one is freshly opened. If it fits the apps in the protect list, the app locker will intercept and show a challenge screen for you to unlock the app.

The Exploit

Let’s see how we can bypass or disable the app locker.

Let’s say you are using the app locker to protect some of the apps with personal data, like the File Manager, expense manager etc, but you didn’t lock up the “Settings” app. All I need to do is to go to “Settings -> Apps”, find the app locker and press the “Clear Data” button. Boom! All your protection is reset immediately. This doesn’t apply only to app locker, it applies to all apps that come with a PIN protection, particularly the Play Store app.


And more…

So you have decided that you should protect the “Settings” app as well and you will be safe after that. Hold that thought! The next thing I will do is to go to the App Drawer, find the app locker and drag it to the Uninstall bin. Boom! All your app protection is gone, again.

And if that is not possible, then I can go to the File Manager, System tools, or even Titanium Backup (these apps are commonly found in most Android phone) and make use of the Uninstall function to uninstall the app locker.

The solution

The solution is very easy. The app locker is useful only if you are protecting the correct apps. While there are plenty of app locking apps in the Play Store, not all of them are made equal. Some of them are way too simple to be of any use (and still charge you for it).

1. First, install an app locker that can protect the “Settings” app as well as protect against installation / uninstallation of apps.

2. Run the app locker and start to add the essential apps to the protect list. Here is the list of apps that you should protect:

  1. The Settings app
  2. Package Installer – protect against installation and uninstallation of apps
  3. Play Store app and any other AppStore app (such as Amazon AppStore)
  4. Any app that have the ability to install/uninstall apps – such as File Manager, Titanium Backup, System Tools etc
  5. Online storage drive such as Dropbox, Box, Drive, Skydrive, Sugarsync etc

and of course, any other app that contain your confidential data.

As an additional security, you should also disable the ability to install app from unknown source. Enable it only when you need to, and disable it again once you are done.


The app locker is as secure as you allow it to be. If you don’t bother to lock up the necessary apps, it doesn’t matter how much you pay for the app locker, they are useless at the end of the day.

Image credit: Norebbo


Damien Oh started writing tech articles since 2007 and has over 10 years of experience in the tech industry. He is proficient in Windows, Linux, Mac, Android and iOS, and worked as a part time WordPress Developer. He is currently the owner and Editor-in-Chief of Make Tech Easier.

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