Enseal

Enseal encrypts the files that matter and keeps them in your own iCloud Drive. Your password is the only key.

• Files are encrypted on your iPhone or Mac before they reach the Enseal folder in iCloud Drive. iCloud holds only ciphertext; names, sizes and types are inside it too.
• On another iPhone or Mac, sign in to the same iCloud, install Enseal and enter the password: everything is there.
• Encrypted files can be backed up, AirDropped and forwarded; without the password nobody can open them. You can also export a copy with its own password for someone else.
• Add from Files or Photos, or shoot straight into Enseal with the camera, bypassing Photos. Photos and videos are stored exactly as they are; nothing is stripped.
• View images, PDFs and videos inside Enseal; videos are decrypted while they play and never touch the disk. Small text files can be edited in place.
• Add a whole folder and its structure stays as it was; folders can be renamed, moved and exported whole. Search, multi-select, rename, export the original. Locks itself when idle for a while or the moment you leave the app.
• Built on libsodium: Argon2id derives the key from your password, XChaCha20-Poly1305 encrypts every chunk. The file format is documented, so the files do not depend on this app.

No account, no network, no data collection. There is no password recovery: if you forget the password, the files are gone.