A free program for Android, by Tribble Advertise.

Face Screen Lock Prank is a very cool app that you can use to make a prank on your friends and family members. This application is very easy to use and it works perfectly on all Android devices. 

To make this prank work, you will need to download and install the app on your device. The installation process is very easy and you don’t need to do anything else. To set a password, just choose a password and enter it. To unlock your phone, you will need to enter the same password. This app is very easy to use and you will be able to make a prank on your friends in a very easy way.