Your mobile phone has become your address book, your bank, your photo album, and your inbox.All of this is contained in a single device that you always carry with you. This means that if someone gets their hands on something they shouldn't, they can see everything from your most intimate chats to your bank details in a matter of seconds. Luckily, nowadays there are many ways to protect access to apps and add different layers of security.
Protect access to applications with a password, PIN, pattern, or biometrics It's one of the best measures you can take to protect your privacy. Whether it's to prevent your children from accessing inappropriate apps, to avoid prying eyes when you lend your phone, or to minimize damage in case of theft, blocking specific apps on Android and iOS is much easier than it seems, as long as you know where to tap.
Why it's worth encrypting and locking your apps
Apps now hold most of our sensitive informationMessaging, social media, banking, email, medical records, private photos… If someone manages to bypass the general lock on the phone (or you have it unlocked, which still happens), they can open everything without resistance unless you have the applications protected individually.
Putting a password on applications offers several clear advantagesIt prevents unauthorized access to sensitive accounts, lets you control which apps other people use when you lend them your phone, and adds an extra layer of protection if you lose your device or it gets stolen. It's not a silver bullet, but it's a very powerful complement to a traditional screen lock.
In addition, many manufacturers have improved their encryption and locking systems in recent yearsintegrating specific app locking options, encrypted secure folders, and biometric authentication. And if your phone doesn't have any of this, you can always use fairly mature third-party apps that add these features without too much hassle.
However, before starting, it's a good idea to make sure you have a stable connection.Because some solutions require downloading apps or updating the system. Incidentally, having a good data plan and decent coverage helps keep your phone up to date with security patches and new versions of Android or iOS.
General methods for protecting apps on Android and iOS
Both Android and iOS offer three main ways to protect applicationsand complement each other: options that come standard in the system itself or in the manufacturer's layer, internal settings in certain specific apps, and third-party tools designed only to block and encrypt applications.
1. Mobile settings and native functionsMany Android manufacturers (Samsung, Xiaomi, Huawei, Oppo, Realme, Vivo, some recent Pixel phones, etc.) include specific sections like "App Lock," "Secure Folder," or similar. From there, you can choose which apps you want to protect and assign them a PIN, pattern, password, or biometric unlock.
2. Security from within the application itselfSome key apps, such as WhatsApp, Telegram, and Google Drive, integrate their own internal locking system. This is usually activated in the app's privacy or security settings and allows you to require a fingerprint, Face ID, or PIN each time someone tries to open it.
3. Specialized third-party applicationsIf your device doesn't offer a built-in lock, or you want more advanced options, there are apps on Google Play that let you password-protect any app, take photos of intruders, hide icons, encrypt galleries, and more. On iOS, due to Apple's restrictions, these solutions are more limited, but some still function as additional secure environments.
Regardless of the method, it is key that the mobile phone itself has a strong screen lock. (PIN, strong password, fingerprint, or facial recognition). Securing an app is useless if the entire device unlocks with a trivial gesture or, even worse, without any code at all.
How to password-protect apps on Android
On Android things get a little more complicated because each manufacturer has its own interface. (One UI, MIUI, EMUI, ColorOS, Realme UI, FuntouchOS…) and the menus change names. The good news is that almost all of them offer some way to block apps individually; and if not, there's always the option of using third-party applications.
Block apps from your phone's settings
Many Android phones include a section for “App Lock”, “Privacy” or “Secure Folder” Within the settings. From there you can choose which apps you want to protect and define the unlock method. The advantage is that you don't need to install anything extra and they usually integrate well with the system, taking advantage of the device's internal encryption.
The exact names of the options may vary depending on the Android version, region, or model.So, if you don't see them right away, try using the settings search function and typing "app lock," "secure folder," or "privacy." In some cases, the feature only appears after you've first set up a general screen lock.
Huawei and Honor (EMUI): App Lock
On Huawei and Honor devices with EMUI, the "App Lock" feature is built-in. and allows you to protect any app with PIN, password, pattern, fingerprint and even facial recognition on recent models with EMUI 14.
The typical path is Settings > Security (or Security and Privacy) > App LockOnce there, you activate the feature, choose your unlock method, and select the apps you want to protect. From that moment on, every time you try to open them, the system will request the corresponding authentication.
If you can't find the option, it may be in another section or your model may have slight differences.In that case, the quickest way is to search online for "your Huawei/Honor model + app lock" or consult the user manual for the exact path.
Samsung: Secure Folder and App Lock
At Samsung, the crown jewel for protecting apps is the famous "Secure Folder" in One UI.It is an encrypted container where you can put applications, photos and files, all under the same additional unlocking method (PIN, pattern, password or biometrics).
The usual path is Settings > Biometrics and security > Secure FolderThis is where you configure the lock type for the first time, and once created, you can add the apps you want to duplicate inside. The apps you put in the Secure Folder are isolated from the rest of the system and will only be visible after bypassing this second lock.
In some recent Samsung models, "App Lock" also appears as a separate option.This feature, accessible from Settings > Security and Privacy, allows you to directly block installed apps without needing to duplicate them within an encrypted folder.
Xiaomi (MIUI): Improved App Lock
Xiaomi phones with MIUI have been offering a complete "App Lock" system for years.With MIUI 15, the interface has also been refined, facial recognition support has been added to many models, and the management of which apps are protected has been simplified.
You can usually go to Settings > Privacy and security > App lock Or, depending on the version, go to Settings > Apps > App lock. There you choose whether you want to use a PIN, pattern, password, fingerprint, or face, and select each app you don't want to open without your permission.
Another option on some Xiaomi devices is to use the system's "Security" app.where the shortcut to App Lock is usually found. The beauty of this solution is that it works natively, and you don't have to rely on third-party tools for something so sensitive.
Google Pixel, Oppo, Realme and other manufacturers
Google Pixel phones with Android 14 have incorporated an individual app locking systemThis feature, which didn't exist in stock Android, is typically found in Settings > Privacy > App Lock. From there, you can choose your unlock method and which apps will be protected.
Oppo (ColorOS) and Realme (Realme UI) share virtually the same systemSince their layers are related, on these phones you need to go to Settings > Security or Privacy > App Lock. First, set a privacy password or PIN, associate fingerprint/face protection if desired, and then select the apps you want to lock.
On the latest Realme phones, the flow usually goes through Password and security > Fingerprint > App lockOnce activated, you complete the process in the Privacy > App Lock section by choosing which programs will be protected. It's a fairly flexible system and, when properly configured, adds a very robust layer of security.
Brands like vivo, with FuntouchOS, also include a built-in app blockerIn this case, it's usually managed through the iManager app, by going to "App Encryption," setting a password, and selecting the apps to protect. The approach is the same: a specific password on top of the phone's general lock.
Other locking tools offered by Android
Beyond classic blocking methods, some Android devices allow you to "pin" an app so that the phone can only be used for that app.This trick is great when you lend your phone to a child or someone else to use a specific app, preventing them from switching to others.
The idea is to pin an app from the recent apps view.To do this, open the multitasking menu, select the app (for example, Skype), tap its icon or the top of its card, and select "Pin this app" (or "Pin screen," depending on the manufacturer). To exit this mode, press and hold the recent apps and back buttons simultaneously, which will return you to the lock screen.
If you have a screen lock system set up, no one will be able to get past it without your PIN or biometric authentication.It's a quick solution to let someone use only one app without setting up complex locks or touching anything else in the system.
How to set a password and lock apps on iPhone (iOS)
Things have changed quite a bit on iOS in the last generationFor years, Apple's system didn't allow natively locking individual apps, beyond workarounds with "Screen Time." With iOS 18, a direct feature to protect specific apps with Face ID, Touch ID, or the device passcode finally arrives.
Native lock with Face ID or Touch ID in iOS 18
With iOS 18 you can require biometric authentication every time someone opens a specific appApple has made the process very simple: just press and hold the app icon on the home screen until the context menu appears.
In that menu, select the option “Require Face ID” (or Touch ID, depending on the model) and it's confirmed when the system requests it. From then on, whenever you try to open that app, the Face ID/Touch ID authentication box will appear, or you'll be asked for your iPhone passcode.
In addition, Apple has added the ability to hide apps and require Face ID to display them.In some cases, you can choose "Hide and require Face ID," which will remove the app from your home screen, search results, notifications, and Siri suggestions. To find it, go to the App Library and open the "Hidden" folder, where you'll be prompted to authenticate again.
Protect apps on iOS 17 and earlier with Screen Time
In iOS 17 and earlier, there was no direct app lock.However, a similar effect could be achieved with the "Screen Time" feature. This tool, designed to control the time you spend on your phone, also allows you to restrict apps using a code.
The trick is to create a ridiculously small time limit for the appFor example, one minute per day. First, activate Screen Time from Settings > Screen Time, set a specific passcode for that section, and then go to "App usage limits" to add the app or group of apps you want to restrict.
After that minute has passed, the app appears locked and can only be used again by entering the Screen Time code.It's not as elegant as the native iOS 18 lock, but it prevents anyone from opening certain apps without your permission if they exceed the limit you've set.
Third-party apps to strengthen security on iOS
Apple is very strict with apps that try to block other apps.Therefore, iPhones don't have app lockers as aggressive as those on Android. Even so, tools like Lockdown Apps and similar solutions exist that act as secure environments where you can group certain functions and require authentication to access them.
These apps typically function as a "private space" within the iPhone itself.Adding a passcode or additional Face ID to access your content doesn't replace the native iOS 18 lock, but it can be a useful extra if you need to further compartmentalize your information.
Block WhatsApp, Telegram, and other sensitive apps
Many applications that handle particularly sensitive information include their own internal locking systems.This is very convenient because you don't depend on the mobile phone manufacturer or third-party apps: everything is controlled from the application's own settings.
WhatsApp, for example, allows you to activate fingerprint lock on Android and Face ID or Touch ID on iPhone.In the app's privacy settings, you'll find the option to require authentication to open it, and you can choose the waiting time: immediately, after 1 minute, after 30 minutes, etc.
It's important to note that this block only prevents the full app from opening.You'll still be able to reply to messages from notifications or answer WhatsApp calls without unlocking your phone. Even so, it adds an extra layer of protection that makes it much harder for someone to snoop through your chats.
Both WhatsApp and other apps like Telegram also offer two-step verificationAn additional PIN is requested occasionally or when logging in on a new device. It doesn't block the app itself on a daily basis, but it does prevent account hijacking attempts and unauthorized remote access.
In Telegram, on the other hand, you can set a lock code for the application itself. From Settings > Privacy and security. It even displays a padlock at the top of the interface so you can manually lock it with a quick tap when you're finished using it.
Third-party apps to password-protect applications on Android
If your Android phone doesn't come with any app locking features built-inOr, if the included options aren't enough, the solution is to download specialized apps from the Google Play Store. These tools have matured over the years and offer very comprehensive options.
AppLock (DoMobile Lab) is one of the queens of the sectorWith over 100 million downloads and very positive reviews, it allows you to lock almost any app (Facebook, WhatsApp, Messenger, calls, Gmail, Snapchat, Play Store, etc.) with a PIN, pattern, or fingerprint, as well as protect system settings to prevent unauthorized access.
This app includes advanced features such as the “intruder selfie”It takes a photo with the front camera when someone enters the wrong password, or uses a random keyboard to prevent someone from memorizing your PIN by seeing where you press. You can also hide the app icon, change it to a fake one, or manage an encrypted "photo vault" to store private photos and videos.
Another popular candidate is Application Lock, developed by InShot Inc.It stands out for its simple interface and for allowing locking via pattern, fingerprint, or password. Many users appreciate it because it can be set up in minutes and delivers exactly what it promises without much extra hassle.
AppLock – Fingerprint (Lock) offers very powerful features for advanced usersFeatures include fingerprint, PIN, or pattern lock, call restriction, WiFi and Bluetooth connection control, automatic blocking of newly installed apps, and more. However, some users complain about the amount of advertising, which is quite common with these types of free tools.
In the past, Norton App Lock was a highly respected benchmark for its simplicity and for coming from a well-known security brand.However, its support ended on June 11, 2024, so it's no longer a recommended option for the future. Many users have migrated to alternatives like DoMobile's AppLock or similar apps.
In any case, the usage pattern of these applications is similarYou install them from Google Play, open them, set up a master PIN or pattern, grant them accessibility permission so they can overlay other apps, and select which apps you want to block from a list. From that moment on, every time someone tries to open them, the locker's own lock screen will appear.
It's always a good idea to check the permissions they request and other users' opinions. Before installing an app like this, keep in mind that they'll have a lot of visibility into everything you do on your phone, so it's important to choose options with a good reputation and clear privacy policies.
Passkeys and password managers: another piece of the puzzle
In addition to app blocking, "access keys" or passkeys have gained prominence in recent years.This system allows you to log in to websites and services without using traditional passwords. Instead of memorizing passwords, it uses device unlocking (fingerprint, face, PIN, or pattern) for verification.
To create a passkey in a compatible app or website, you usually first need to register as usual.Afterwards, the service offers the option to generate an access key, which is linked to your account and stored in the device's password manager (such as Google Password Manager or third-party solutions like Samsung Pass, Keeper, or 1Password).
On Android you can choose which password manager you want to use to save passkeys From Settings > Passwords, access keys, and accounts. Once configured, when an app or website allows it, you'll be prompted to log in directly using your access key and screen unlock, without typing anything.
Passkeys do not replace local app locking on your mobile device.However, they do significantly improve the security of online accounts and reduce the risk associated with weak or reused passwords. Combined with good app locks and a protected screen, they form a very robust security system.
Extra tips to make your mobile phone harder to "hack" at home
Beyond activating locks and passwords, there are a number of best practices that should be internalized. So that your privacy doesn't depend solely on a hidden option in the settings. They're simple details, but they make all the difference.
The first thing is to use a strong screen unlock method and not share it with just anyone.No obvious four-digit PINs like 1234 or your birthday. If your phone allows it, combine a PIN or password with a reliable fingerprint or facial recognition (not systems that unlock with a simple photo).
Always keep your system and apps updatedBecause many updates patch important security vulnerabilities. Having a good data or Wi-Fi connection helps, as it prevents you from delaying patch downloads for fear of using up your data allowance.
If you're going to install third-party apps to block applications, always download them from official sources. (Google Play Store, App Store) and carefully review the permissions. Legitimate blocking apps need accessibility and some advanced access to function, but they shouldn't request things that don't make sense for their purpose.
Finally, take advantage of all the tools that the applications themselves already offer.This includes measures such as two-step verification for WhatsApp, Telegram, and other services, as well as encrypted backups, and private chat or gallery locks. The more barriers you put up against prying eyes, the more secure your data will be.
Protecting access to mobile applications by combining device lock, native Android or iOS features, internal settings of each app, and, if necessary, reliable third-party tools allows you to transform your phone into a kind of digital safe. where each important door requires its own key, minimizing the chances of someone snooping into your digital life without permission.
