When your booth is unattended, guests can accidentally (or intentionally) leave the app, open other apps, or change device settings. Android's built-in App Pinning (also called Screen Pinning) locks the device to LumaBooth so guests can't leave it without your PIN. This is the Android equivalent of Guided Access on iPad.
Enable App Pinning
Open your device's Settings app.
Go to Security (on Samsung: Security and privacy, More security settings).
Find App pinning (sometimes called Pin windows or Pin app) and switch it on.
Also enable Ask for PIN before unpinning. Without this, anyone can unpin the app.
Pin LumaBooth
Open LumaBooth and start your event.
Open the Recents view (swipe up and hold, or tap the Recents button).
Tap the LumaBooth icon at the top of its preview card.
Select Pin (or Pin this app).
Unpin When the Event Is Over
Swipe up and hold (or hold the Back and Recents buttons together), then enter your device PIN.
The exact menu names vary by manufacturer. For detailed step-by-step instructions for Samsung and Lenovo tablets, see How to Enable and Use App Pinning on Android Devices.