App Lock - Applock Fingerprint

Review by eFreeware

Most privacy apps ask you to trust a black box. App Lock by Trusted Tools takes a different angle: it puts a visible gate in front of the apps you choose, unlocked by a PIN, a pattern or your fingerprint, and it adds a disguise so the gate itself is harder to spot. That combination of obvious protection and a hidden identity is the most distinctive thing about it, and it is why the app has passed 100 million installs with a 4.7 average from a large body of ratings.

The people who get the most from it are those who share a device rather than own one outright. A parent whose phone is passed around at the dinner table, someone whose work handset is used by colleagues, or a household where a single tablet serves several people: all of them face the same problem, which is that a phone has no natural door. App Lock is built to add one, and to keep adding it after you close an app or turn the screen off.

It is a free download, and the protection sits alongside a commercial layer rather than behind a one-off price. I would treat it as a utility you set up once and then mostly forget, which is the right shape for this sort of tool.

The everyday job: locking apps and files

The core of the app is a list of installed apps you can put behind a lock. Social apps such as WhatsApp, Instagram and Facebook are typical targets, along with Gallery, Contacts and Messages, so the intent is broad: anything that would embarrass you or someone else if it were opened by the wrong hands. Once an app is on the list, opening it means clearing the PIN, pattern or fingerprint prompt first.

There is a second, more practical use that I think is underrated. Payment apps such as Google Pay and PayPal can be locked too, which the developer frames as a way to avoid accidental payments and to stop children from buying games. That is a different problem from secrecy, and it is a good fit for a shared phone where a child plays games on the same device that holds a wallet.

The Safe Vault takes the same idea further by hiding photos and videos. Files placed there do not appear in the gallery, and the developer says only someone who enters the password can view them. For anyone whose camera roll doubles as a personal archive, that separation is the feature that justifies the install on its own.

A few smaller options round out the daily routine. The pattern draw path can be hidden so nobody watching over your shoulder sees the shape you trace, the keyboard can be randomized so a password cannot be guessed from finger position, and relocking can be set to trigger after you exit an app, after the screen turns off, or after a custom interval. Newly installed apps can also be detected and locked in one step rather than one at a time.

Intruder selfie and the disguised icon

Two features go beyond simple gating. The first is the intruder selfie: if someone tries to open a locked app with the wrong password, the app captures a photo automatically. The value here is not prevention but evidence, and for a parent or a manager trying to work out whether a device is being probed, that record is more useful than another lock screen.

The second is disguise mode, which replaces the app's own icon with that of another app so the locker is harder to find on the home screen. It is a small touch, but it answers a real weakness of this category: a lock screen announces that something is being hidden, whereas a disguised icon does not. The developer's stated aim is to confuse anyone peering at the device.

Uninstall protection belongs in the same group. The developer says it prevents hidden files from being lost if the app is removed by accident, which addresses the obvious failure mode of a vault, where a single careless tap could wipe the very things you were protecting. Alongside these, multiple lock screen themes are available for anyone who wants the lock screen to match the rest of the phone.

What it asks for, and what that means

Two permissions are worth understanding before you install. The app requests All Files Access so it can hide private photos, videos and other files, and this access is used only for protecting files. It also requests Location access at all times, including while running in the background, to support the Trusted Wi-Fi feature, which keeps selected apps unlocked while the device is connected to networks you have marked as trusted.

That second permission is the one I would think about hardest. Always-on location is a meaningful ask for a locking utility, and the trade is a convenience feature rather than a core one: you get fewer prompts at home or at the office in exchange for a broader permission. It is a reasonable bargain for some people and an unnecessary one for others, and the choice is yours to make at setup.

The recovery path is also worth setting up on day one. The app supports a recovery email that can be used to reset a forgotten password, and the password can be changed later from Settings. Those two details are easy to skip when you are eager to start locking things, and they are exactly the ones you will want later.

Price, advertising and purchases

App Lock is free to download. It contains advertising and it offers in-app purchases. Those terms place the app in the familiar free-with-ads bracket rather than in the paid-utility bracket.

What that means in practice is a trade: you get the locking, the vault, the intruder selfie and the disguise without paying up front. I would not describe this as a hidden cost, because both facts are stated plainly, but it is a factor if you dislike advertising inside a tool that is supposed to be discreet.

Content is rated for Everyone, and the app has been available since November 2022, with an update in September 2026. The install count and the rating suggest a tool that a very large number of people have adopted and, on the whole, kept.

How it compares with the alternatives

There are three broad routes to the same goal, and it helps to know which one you are choosing. The first is the protection built into the phone itself, which is free and already installed but tends to be coarse: it locks the device, not individual apps, and it does not hide files in a separate vault.

The second is a password manager or encrypted storage app. Those are excellent at keeping secrets in one place, but they are not built around the moment-to-moment act of opening an app, and they do not photograph someone who fails a login. The third is a dedicated locker like this one, which is the only category that combines an app-by-app gate, a hidden vault, an intruder record and a disguised icon in a single place.

Within that third category, App Lock competes on breadth rather than on a single trick. The fingerprint, PIN and pattern options, the payment-app locking, the relock timing and the Trusted Wi-Fi behavior are the details that separate it from a bare-bones locker, and they are the reasons I would look at it before a simpler option.

A sensible choice for a shared phone

App Lock is a well-rounded privacy tool for a specific situation: a device that other people can pick up. If your phone stays in your pocket, the built-in lock screen may be enough, and the always-on location permission will look like a poor trade. If your phone is shared with family, colleagues or children, the combination of app locks, a hidden vault, an intruder selfie and a disguised icon covers the gaps that a device PIN leaves open.

The free download, the advertising and the in-app purchases are the price of entry. The permissions are the other consideration, and they are stated clearly enough that you can decide before installing rather than after.

I would set a recovery email before locking anything, decide deliberately whether Trusted Wi-Fi is worth the location access, and then let the app do its quiet work. For the shared-device problem, that is a reasonable bargain, and the install numbers suggest plenty of people have reached the same conclusion.