The short version. A calculator vault opens as a working calculator. Type a code, press equals, and a private area appears with the photos and files you put there. The calculator part is easy and every app does it well. The part that matters — whether the files behind it are actually encrypted — varies enormously, and no listing tells you which you are getting.
The single most useful thing on this page. In a meaningful number of these apps the calculator is the entire security model. The photos sit in the app's own folder as ordinary readable files. Anyone who plugs the phone into a computer, or restores a backup, or simply installs the same app and pokes at it, has them. A front door is not a lock if the wall behind it is missing.
What they can and cannot do on iPhone
Much of what you will read about calculator vaults is written about Android, where a launcher can genuinely conceal other apps. iOS does not permit that, and the difference matters:
| iPhone | Android | |
|---|---|---|
| Hide other apps | No. iOS does not allow it | Yes, with some launchers and hider apps |
| Hide photos and files you import | Yes | Yes |
| Show a calculator as the opening screen | Yes | Yes |
| Change its own icon and displayed name | Limited: only to icons shipped in the app, and the feature must be described in the App Store listing | Broadly, at runtime |
| Disappear from the device's app list | No | Sometimes |
That last row is the ceiling nobody mentions. On iPhone, every installed app appears in Settings → General → iPhone Storage, in Settings → Apps, and in Screen Time — under its real App Store name, whatever the home-screen icon shows. There is no setting, and no app, that changes this.
So a calculator disguise defeats someone who glances at your Home Screen. It does not defeat someone who opens Settings and scrolls. Knowing which of those you are dealing with is the whole decision.
Why App Review allows this at all
App Store guideline 2.3.1 forbids hidden features — functionality a reviewer cannot find and users are not told about. A disguise screen is allowed when it is the opposite of hidden: named in the app's own Settings, described in the App Store listing, and explained to the reviewer.
This is why iPhone calculator vaults are less covert than the Android write-ups suggest, and it is also a useful filter for you. An App Store listing that describes its disguise feature openly has been through review with it. A listing that is coy about what the app does has either not been reviewed for it or is describing something else.
Five checks before you trust one with anything
1. Encrypted files, or just a locked door?
The question to look for in the listing or the app's own documentation: are the files encrypted with a key derived from your password? Phrases worth seeing are AES-256 and a key-derivation function such as PBKDF2 or Argon2 with a stated number of rounds. Phrases that mean nothing on their own: "military-grade", "bank-level", "secure servers".
A quick, imperfect test you can run yourself: put one throwaway photo in, then connect the phone to a computer and look at whether the app's documents are browsable. If you can see your picture, so can anyone else with the cable.
2. Does it want an account?
An app whose purpose is that nobody knows what you have, which begins by asking for your email address, has an awkward first paragraph. It is not automatically disqualifying — but understand that you have identified yourself to a company before hiding anything.
3. What is the privacy label?
On the App Store listing, scroll to App Privacy. "Data Not Collected" is the only answer that matches the promise these apps make. "Usage Data" or "Identifiers" in a privacy app is a contradiction you are allowed to hold against it.
4. Can you get everything out, free?
Before you put three hundred photos anywhere, find the export. One file, or one folder, all of it, without paying. If the only way out is one photo at a time, or is behind a subscription, you are not storing your photos — you are lending them.
5. What happens when you stop paying?
Viewing, exporting and deleting what you already own should never stop working. Some apps lock you out of your own photos when a trial ends, and their one-star reviews say so at length. Read those reviews specifically — sort by Most Critical and search for "lost".
The failure mode that actually loses people's photos
It is not someone cracking the encryption. It is this sequence, which repeats in the one-star reviews of every app in this category:
- Import a few hundred photos into the vault.
- Delete the originals from Photos to free up space.
- Months later: new phone, a bad update, an uninstall, or a forgotten password.
- The vault was never backed up, because it is deliberately outside the normal photo backup.
Whatever app you choose, set up its backup or export on day one, and check that the export actually opens on a computer. A vault with no way out is a single point of failure that you built yourself.
The variant that is more useful than a calculator
A disguise screen answers "someone glanced at my phone". It does not answer "someone is standing here asking me to open it", because at that point you unlock the app and everything is there.
The feature for that is a second password that opens a different vault — a real, working, separate space with ordinary content in it. The app looks fully opened; the other vault is not on screen and nothing indicates it exists. Fewer apps offer this than offer calculators, and it is the more meaningful of the two by a distance.
Where we stand
Hushfold has both: five disguise screens and four alternate icons, which are free, and a decoy vault behind a second PIN, which is in the paid tier. We name the tiers here because a page about apps that hide what they do should not be vague about what you get for nothing. All of them are listed in its own Settings and described in its App Store listing, because App Review requires that and because a feature you cannot find is a feature you cannot rely on.
On the five checks above: files are AES-256-GCM with a key derived from your password using 600,000 rounds of PBKDF2; no account and no email; the privacy label is Data Not Collected; the full export to a single file is free and always will be; and viewing, exporting and deleting are never behind the paywall, including for photos above the free limit.
And the honest counterweight, because this page is worth more to you than a sale is to us: the disguise is the weakest thing on that list. The encryption, the no-account design and the free export are what actually protect you. If you take one thing from this page, take the five checks and apply them to whichever app you choose — including ours.
Next: how to hide apps on iPhone, and the four places they still appear · how our encryption works
Frequently asked questions
Can I hide apps using a calculator?
On Android, some launchers and hider apps can genuinely conceal other apps. On iPhone they cannot — iOS does not let one app hide another. An iPhone “calculator vault” hides photos and files that you import into it, not other apps. If an iPhone listing claims it hides apps, it is describing an Android feature.
Which calculator is best for hiding apps?
Judge them on what happens to the files, not on how convincing the calculator is. Ask whether the photos are encrypted with a key derived from your password, whether an email or account is required, and whether you can export everything for free. A beautiful fake calculator in front of an unencrypted folder protects nothing.
What is the sneaky calculator app?
It is a general name for apps whose opening screen is a working calculator, and which reveal a private area when you type a code and press equals. Dozens exist on both stores. On the App Store the feature has to be described in the listing, so it is a declared disguise rather than a secret one.
Is there an app to hide apps?
On iPhone, iOS itself is the answer: touch and hold an app, tap Require Face ID, then Hide and Require Face ID, and it moves to a locked Hidden folder in the App Library. No third-party app can do more than that, because iOS does not give apps that power.
How to hide apps very secretly?
There is a ceiling on iPhone and it is worth knowing where it is. Every installed app appears in Settings → General → iPhone Storage, in Settings → Apps, and in Screen Time, whatever its icon says. Nothing removes it from those lists. The realistic goal is an app whose presence is unremarkable, not one that is invisible.
What do decoy apps look like?
Usually a calculator, occasionally a notes app, a clock, a unit converter or an audio player. The good ones are fully working versions of the thing they resemble, because a calculator that does not calculate gives itself away the moment someone taps a number.