Don’t you hate it when you hand your phone to someone to show them a cool new game, and next thing you know they’re scrolling through your photo library? [quick skit: phone handed to someone from offscreen. “Hey check out this cool new game!” person receives the phone, starts swiping furiously, jaw drops in shock.] Well if you have Android 5.0 or later, you have a built-in solution for that. It’s call Screen Pinning, and here’s how it works. Make sure screen pinning is enabled. In Settings - > Security Scroll down, make sure Screen Pinning is ON When you’re in an app, hit the recent apps button. Hit the pin. Warning pops up
To unpin- press and hold the back and recent apps button at the same time. Of course, if the person you’re handing your phone to knows how to un-pin your app, it doesn’t help you. That’s why there’s a little checkbox in the screen pinning confirmation box that says “ask for unlock pattern before unpinning.”
Also, note that this only locks your phone to one app, not one screen. If you pin your phone to your photos, they can’t get to your other apps, but they can still swipe through your photos. So be careful before handing your phone over to your annoying (refer to whoever it is that we just saw in the skit).