Rune

Rune is a calm, fast notes app for people who don't want to trust an app with their data. Your notes never leave your device, they are encrypted at rest, and the app makes no network connections at all. There is no account, no cloud, and no sign-up.

Privacy by construction, not by promise:

• No telemetry, no analytics, no crash reporting, no advertising, no tracking — none, not "anonymised", not "aggregated".
• No networking code. Put your device in airplane mode and everything still works. If anything ever tries to reach the network, that is a bug.
• No account and no server. There is no "we" that could hold your data.

Real encryption:

• Your passphrase derives a key with Argon2id; notes are sealed with XChaCha20-Poly1305 authenticated encryption. Only ciphertext is ever written to disk.
• The passphrase is never stored and is not recoverable. If you forget it, your notes are gone — no reset, no backdoor. That is the price of real privacy.
• A wrong passphrase simply cannot decrypt your notes.

What you can do:

• Create, edit, search, and organise plain-text notes with an Apple-Notes-style layout that adapts from phone to desktop.
• Auto-lock on inactivity and lock-on-background; the app starts locked.
• Export an encrypted backup (safe to keep anywhere); plaintext export is gated behind an explicit warning.
• Capture voice notes — recording stays entirely on your device.

Free and open source under the GNU GPL, version 3 or later. The security-critical code is a small, dependency-light, pure-Dart core so it can be read and audited. Releases published on GitHub ship with cryptographic provenance (SLSA build-provenance attestations and a keyless cosign signature) so you can verify those binaries were built from this source. Builds distributed by F-Droid are built and signed by F-Droid itself and are not covered by that provenance.

This is honest software: it tells you what it does not yet do. See the project's SECURITY.md for the threat model and current limitations.