"Password protect an app" usually means one thing on Android: require some form of authentication — a PIN, a password, or biometrics — before the app is allowed to open, separate from your phone's main lock screen. There are a few different ways to get there, with different tradeoffs.
Option 1: Built-in manufacturer app locking
Some Android phones include app-locking as a system feature, tucked into security settings. Where it exists, it's convenient because there's nothing extra to install. The downside is inconsistency — not every manufacturer includes it, and the ones that do vary in whether it supports biometrics, how quickly locked apps re-lock, and whether it's easy to find and turn off by anyone else using your phone.
Option 2: A dedicated app-locking app
App Lock as a standalone feature gives you consistent behavior regardless of phone manufacturer: pick which apps to lock, set a PIN or biometrics, and locked apps re-lock automatically once they leave the foreground.
Choose your unlock method
PIN is the reliable baseline; biometrics (fingerprint or face) are faster day-to-day where your device supports them.
Select the specific apps that need it
Messaging, banking, galleries — whatever you don't want opened without a check. Locking everything adds friction without much added benefit.
Confirm apps re-lock automatically
An app lock that stays "unlocked" all day after one check isn't doing much. Confirm the app re-locks once you switch away.
What a password on the app doesn't cover
Locking an app restricts who can open its interface — it doesn't encrypt files that app has already saved elsewhere on your phone. If the goal is protecting specific files rather than an entire app's interface, that's a job for a Private Vault instead, which encrypts the file itself.
Password protect your apps
Lockilee's App Lock is free to start, with 10 slots across files and locked apps.
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