I handed my phone to a stranger at the airport to show my boarding pass. He scrolled up. There was nothing bad there, but I watched his thumb move and felt my stomach drop.

The Night Agent Season 3 drops today. A show about phone calls, encrypted messages, and not letting the wrong person see your screen. Your Android phone has a security feature that does exactly that.

Quick answer: Android Screen Pinning is a security feature that locks your phone to a single app until you unpin it with your PIN. To enable it: open Settings, tap Security & privacy, tap More security settings, tap App pinning, and toggle it on. It’s filed under a name (“App pinning”) that nobody would search for unless they already knew it existed.

What it does

Screen Pinning locks your phone to a single app. Hand someone your phone to show them a photo — they can’t swipe to your messages, your email, or anything else. The phone stays on that one app until you unpin it with your PIN.

How to turn it on

  1. Open Settings
  2. Tap Security & privacy
  3. Tap More security settings
  4. Tap App pinning
  5. Toggle it on

Now to pin an app: open your Recent Apps view, tap the app’s icon at the top, and tap Pin this app. To unpin, swipe up and hold — your phone asks for your PIN before unlocking.

Why you’ve never seen it

It’s called “App pinning” and it’s filed under Security, three menus deep. Nobody would search for that name unless they already knew it existed.

Which is a shame, because the use cases are everywhere. Handing your phone to a kid to watch a video. Lending it to someone to make a call. Showing a boarding pass at the gate without worrying about a notification pulling up something private. (If your lock screen is already showing notification content, pinning won’t help with that.)

Screen Pinning keeps people out of your other apps. If you want to keep apps from interrupting you, Focus Mode pauses specific apps on demand. It’s a different buried setting for a different problem.

The bigger picture

Your phone has features like this: genuinely useful, just buried under names nobody would guess. Screen pinning for a boarding pass, offline maps for a road trip, Data Saver for a packed stadium. Each one is in a different menu, with no shared interface that says “you’re traveling.” That’s why we built TrueTo. One place to find the settings that actually help.

Enjoy Season 3. Keep your screen locked down.