A free app for Android, by ProLogicss.

Are you one of those people who find yourself in a situation where you need to keep your phone secure from intruders? Are you one of those people who are afraid that their phone is not secure and is accessible to intruders?

Do you want to eliminate this problem?

If you answered yes to any of the questions above, then this app is for you.

The application is called Knock Door Screen Locker and it is a simple application that can be used on Android phones.

With this app, you can create a secure lock screen that requires you to knock twice or thrice or as many times as you want.

The app has a simple user interface and is easy to use.