How to Lock Apps on Android
Now, modern Android phones and tablets are coming with built-in lock functionality to protect your phone from unauthorized use. In this digital era, everyone is taking advantage of the phone's built-in lock feature and protecting them with fingerprint, PIN, pattern, or face-lock (or all of them). However, sometimes you may need to add extra protection to your apps that hold and access credentials (sensitive) and private information. It helps you protect your data from unauthorized use if other persons (kids, friends, or partners) use your Android phone for any reason.
Some of the phone apps come with a built-in lock feature, and for some apps, you need to install a third-party app on your device to apply a lock on them. In addition, the processes to apply lock apps are different based on the phone operating system you are using (Android or iOS) and the phone model (version).
For Android 10 and Android 9.0 Pie (using built-in device feature)
Apply lock on the app screen to keep it un-access until you unlock.
Now, the lock app is successfully installed on your device. Therefore, you can lock your app with a password, and no one can access that particular app without entering the same password on the app's lock screen. If you want to change your password or want to turn off the app lock, click on the Settings > Biometrics (Fingerprint, face, or password) > Privacy password > enter your password and tap on Change password or Turn off password.
For Android 8.0 Oreo and 7.0 Nougat
If you are using some older version of an Android smartphone, the process and steps to lock apps on them are a bit different.
Locking Apps using third-party apps on Android
Several third-party mobile tools and security master lock apps are available that protect your apps and files from unauthorized use. If you want to protect your personal data, you need to download and install it from the Google Play Store and set it up on your smartphone. you can protect any by implementing a password, pin, pattern, or even using biometric security. When you try to open your locked or protected apps, you have to go through your password, and unless you enter the correct password, the app can't get launched.
However, keep in mind that these apps ask to allow some permission and system privileges while installation to get function. So it is suggested to use only trusted apps.
Norton App Lock
Norton App Lock is a trusted tool for protecting apps and other private files stored on your smartphone. The app is free to download and use from Google Play Store. The app facilitates you to lock your apps with either passcode or pattern drowns lock on the screen. Once you install and set up the Norton App Lock on your smartphone, you can easily protect your apps. Just launch the Norton App Lock and draw an unlock pattern, or you can also use a passcode to unlock the app. Unfortunately, if you forget your pattern or passcode, there is also an option to reset them using your Google account linked with your Android phone.
To lock any apps, launch the Norton App Lock and select the lock next to the app you want to password-protect. Once the app gets locked, only the password that you created earlier will allow it to access.
When we tried it out after locking the app, we navigated to the home screen and started one of the locked apps. The lock appears over the app and prevents it from open. Therefore, an unknown person cannot open and access it without PIN, pattern, or biometrics. You can only unlock the app by providing the correct PIN or pattern.
App Lock from Keepsafe
Keepsafe's App Lock app doesn't allow taking any screenshots while using it. So, all we explain in the text that we observe while using it. When you download and install it, the setup wizard asks you about the type of locks such as PIN, pattern, or fingerprint. If you are already using your fingerprint to unlock your phone, you don't need to register it again to protect or lock any app available on your smartphone. It is because the app uses the fingerprint already stored in your device. It builds trust while using it as the Keepsafe's App Lock can't send your fingerprint to the app creator.
The App Lock asks you about your email address for security, but you can even skip this option if you want. The app takes you to the system settings, where you have to grant access to the data usage. Return to App Lock and select the app you want to lock and protect from unauthorized access.
Create a user or guest account
If you do not want to use any third-party app locker apps from Play Store or any other source to lock apps, there is an alternate option known as the device operating system. Create a second user or a guest account on your smartphone. In this way, you can also be able to protect your apps. The second user or guest account user is the temporary user, and they can't use your main profile. They can't be able to make phone calls, send SMS messages, or access any data present on your phone, including your apps. They are only allowed to install apps and store their data on their phones. You can create it via a button located above the quick settings on the top. If you set it up as a user and not as a guest account, you can even pass the phone to another person to store their data on it.
Locking Apps on iOS
Apple doesn't allow and concession any third-party apps to install on iOS as Google does for Android. So you couldn't find any standard locking tools in the App Store. Instead, you have to trust and work on individual apps themselves. However, many apps on iOS which can store any sensitive information offer an additional protection option to you.
Along with the security that WhatsApp has, it also protects your messages from exposure to unknown people. For this, you have to go to the main screen and click on Settings app. After that, go to Accounts > Privacy & Screen Lock and activate Touch ID or Face ID to prevent your conversations from being accessed.
One other example is Apple's Notes app for its iPhone. It allows you to lock each note by clicking the Share button (present inside the note) or long-pressing on a note and choosing Lock Note. In addition, you can use your PIN code, Touch ID, or Face ID to lock Notes. You can set it via Notes in the iOS Settings app.