Have you ever given your phone to someone and you don't want them to go to other apps or don't want them going through your phone for privacy reasons,e.t.c.This tutorial is for you ;
Step1 Click on the recent button.
Step2
You will see a pin icon click on it .
For Samsung: Hold the app icon and click on pin screen .
How to remove the Pinned screen Hold the return and recent button together.
You will be directed to the lock screen .