“Best” depends on the job: cloud storage, passwords, notes, or files that are nobody's business at all. Here is the field, including where we are not the right pick.
For most private files on an iPhone or iPad, pick a vault that encrypts on your device with AES-256 and needs no account. Sealby does that, and adds deniable hidden vaults with no stored list or count. Pick Proton Drive for encrypted cloud storage at scale, 1Password for credentials, and Standard Notes for cross-platform encrypted notes.
Sealby
Best for private files whose existence itself is private
A vault on your device for photos, videos, documents and rich-text notes. AES-256-GCM encryption, keys in the Secure Enclave, no account and no servers. What sets it apart: different PINs open different vaults, with no stored list or count of them. Free on one device; Premium adds encrypted iCloud backup, sync and vault sharing.
iPhone & iPad (iOS 17+); not a general cloud drive.
Apple built-ins (Hidden album, locked notes)
Best for zero-setup tidiness
Free, already on your phone, and since iOS 16 the Hidden album locks behind Face ID or the device passcode. Fine for keeping casual photos out of the main grid or locking a note body.
Tied to your device passcode, visibly exists, easy to unhide, and split across two apps with no shared vault, search, or independent recovery.
Proton Drive
Best for encrypted cloud storage at scale
End-to-end-encrypted cloud drive from Proton with cross-platform apps, sharing links, and generous paid storage tiers. A strong choice when the job is “my files, encrypted, everywhere.”
Requires a Proton account; your encrypted data lives on their servers; no deniable vaults or duress features.
1Password
Best for passwords first, documents second
The benchmark for credential management, with document storage attached to a mature cross-platform ecosystem and team features.
Account plus subscription required; server-hosted encrypted vaults; not designed for media libraries or deniability.
Standard Notes
Best for encrypted notes across every platform
A long-standing, open-source encrypted notes app with excellent cross-platform sync and a plain, dependable design.
Notes-centric — files and media are secondary; account-based sync; no deniable vaults.
Free photo lockers & calculator vaults (the category)
Best avoided for anything genuinely sensitive
Hundreds of free “photo vault” and fake-calculator apps fill the store. A few encrypt properly. Many only hide files, earn money from ads and tracking, or keep copies on their servers. If you use one, read its App Store privacy label first and check that it explains its encryption.
Hiding is not encryption, a famous disguise is not deniability, and ad SDKs are strange company for private photos.
Choosing well
What actually makes a vault app secure?
Four things to check. Encryption happens on your device before anything is stored or synced, not just “in transit”. Keys stay with you, backed by hardware and never held on a server. Recovery has no backdoor. And the app is honest about its limits: a good vault tells you what it cannot protect against.
Do I need a deniable vault?
If no one ever pressures you to unlock your phone, maybe not. But deniability also covers everyday life: a borrowed phone, a shared passcode, a nosy glance. With a deniable vault like Sealby, there is nothing to find and nothing to explain. That is a quieter kind of privacy.
Is a free vault app trustworthy?
Free is fine when the business model is visible. Sealby’s free tier is the full local vault, and Premium (backup, sync, sharing) pays for it. Be wary of free vaults with ads or tracking code. An app that phones home is a strange place for secrets.