Pin Screen feature on Android allows you to display only one app and restrict access to the rest of the phone. This feature is often used in Mobile Showrooms to display the phones.
This feature can be very useful for parents who give their children a mobile phone. For example, you can pin YouTube, meaning that all other features of your phone are locked. To use this feature you need to follow steps 1 and 2 for the first time:
Step 1: Click on the Settings app on your mobile phone, in the search field and enter “Pin Windows” or “Pin screen” depending on your manufacturer
Step 2: Enable Pin Screen feature as shown below
Once you have completed the above steps, follow the below steps to Pin an app.
Tap on Minimize icon and select the app that you would like to pin
Click on the app icon at the top
Click on Pin to Screen
To un-pin a screen, you will have to press the back and recent windows button at the same time or swipe up , after which you will be prompted to enter the screen lock password to access the other features.