There is an app on your child’s phone that looks exactly like a calculator. But if you type in the right passcode and press equals, it opens to something else entirely: a hidden folder, locked away from you, containing photos, videos, messages, or even entire social media accounts your child has no intention of you seeing.
These are called vault apps, and they are significantly more common among teenagers than most parents realise.
What vault apps actually do
Vault apps are designed to hide content behind a secret login, then disguise themselves as something ordinary. The most common disguise is a calculator, but they also appear as note-taking apps, flashlight tools, or photo managers. Some are sophisticated enough to show a convincing fake interior if someone they don’t trust enters a decoy password, with the real content locked behind a separate code.
The most widely used vault apps right now include Keepsafe, Calculator Vault, Hide It Pro, Vaulty, and Private Photo Vault. Some of these have tens of millions of downloads. They are free, available in the App Store and Google Play, and many carry benign age ratings. Several will also photograph and log anyone who enters the wrong password, alerting the child that someone has been trying to get in.
What parents may not know is that vault apps aren’t just third-party downloads anymore. Both Apple and Google have now built vault-like features directly into their operating systems. On iPhones running iOS 16 and later, the built-in Photos app includes a Hidden Album that can be locked with Face ID. On Android 15, Google introduced a feature called Private Space that creates a completely separate, password-protected area on the device where apps can be installed and hidden. Neither of these features can currently be disabled through Apple’s Screen Time controls or Google’s Family Link, even on a supervised device.
How to spot a vault app on your child’s phone
The honest difficulty with vault apps is that looking for them by icon alone is unreliable. These apps change names regularly, get pulled from app stores and reappear under new ones, and the best-designed ones are intentionally indistinguishable from real utilities. There are patterns worth knowing — and more reliable ways to check.
Common vault apps to look for
Visual red flags
Two calculator icons. Every phone ships with one. A second is almost always a vault app.
A utility app using large storage. A real calculator is a few MB. Any “calculator” using 50MB+ is storing something.
A simple app requesting camera, photos, and contacts permissions — check under Settings > Privacy.
A vague padlock or folder icon from an unknown developer, often named “Private Space” or “Photo Manager.”
How to check — more reliable than looking at icons
App store search
On your child’s phone, search “vault,” “hide photos,” or “secret.” Any result showing “Open” instead of “Get” is already installed.
iPhone spotlight
Swipe down from the home screen. Type “vault,” “secret,” or “calculator+.” Hidden apps still show up here.
iPhone app library
Swipe left past all home screens. Every app appears here — even ones removed from the home screen.
Check storage
Settings > General > iPhone Storage. Any small-looking utility app using unusually large storage is worth a closer look.
Note: app icons above are illustrative. Search your child’s App Store for the exact names to see real icons.
One thing parents on iPhones should also check: open the Photos app, scroll to the bottom of the Albums tab, and look for a folder labelled Hidden. On iOS 16 and later, this folder can be locked with Face ID. If it is there and locked, it is worth having a conversation about what is in it.
Why parents are concerned
The concern is not that teenagers want some privacy. That is normal, developmentally appropriate, and worth respecting. The problem is what vault apps enable when a young person does not fully understand the consequences.
Research published in JAMA Pediatrics found that nearly 15% of teenagers aged 11 to 17 had sent a sexual image, and over 24% had received one. Vault apps are frequently used to store this kind of content, and children often don’t understand that storing an explicit image of a person under 18, including themselves, can be illegal regardless of who took the photo or whether it was shared. If that image is later accessed by someone else and used for blackmail, a child who thought they were being careful finds themselves in serious danger.
Several vault apps have also been linked to sextortion incidents, where vulnerabilities in the apps allowed third parties to access content without the user’s knowledge. The Silicon Valley Internet Crimes Against Children Task Force lists vault apps specifically as tools used in exploitation cases involving minors.
Beyond the legal risks, vault apps can allow a child to hide an entire online relationship from their parents, including contacts, conversations, and photos connected to an adult who may be grooming them. When all of that is locked behind a second password on an app that looks like a calculator, the opportunity for a parent to notice something is wrong becomes much smaller.
What to do if you find one
Finding a vault app on your child’s phone does not automatically mean something serious is happening. Teenagers use them to hide embarrassing memes, keep a personal diary, or store content they consider private. It is also worth knowing that vault apps are not going away — new ones appear regularly, names change, and as shown above, the functionality is now built into the operating system itself.
What matters most is whether your child understands the risks. Many do not know that storing an explicit image of a person under 18, including themselves, can carry criminal consequences regardless of who took the photo or whether it was shared. They may not understand that content they believe is secure in an app can be accessed by others, or used against them.
The longer-term question for families is whether app approval is part of their setup. Both Apple Screen Time with Family Sharing and Google Family Link allow parents to require approval before any new app is downloaded. With vault apps, the window to intervene is the moment of installation, not after.
For more on parental control options and how safe your child’s apps really are, use our Platform Safety Scorecard — independent safety ratings for 16 platforms including the apps most commonly hidden inside vaults.
Platform Safety Scorecard
Check your child’s apps → We scored 16 platforms across six safety categories. Select your child’s age, choose their apps, and get a personalised safety report.
Sources:
JAMA Pediatrics — study on adolescent sexting prevalence
Silicon Valley ICAC — vault apps parents should know about
Qustodio — how to spot a fake calculator app
Boomerang — vault app features now built into Android and iOS
