Koz is a privacy-focused notes app built around one idea. What you write belongs only to you.
Koz never connects to the internet. No accounts, no servers, no analytics, no ads. Everything in your notebook stays only on your device.
SECURITY
• Notes are sealed with AES-256-GCM, the whole database is encrypted with SQLCipher.
• The PIN that unlocks the app also derives the encryption key (Argon2id); the PIN itself is never stored anywhere.
• Unlock quickly with fingerprint or Face ID.
• Emergency password: entering it shows "wrong PIN" on screen, but quietly wipes the vault. Built for moments you're forced to unlock the app.
NOTES
• Organize freely with folders inside folders.
• Attach photos, files, and voice memos, all encrypted the same way as your text.
• Hide any note or folder so it disappears completely from browsing; only you can bring it back.
BACKUP
• Create an encrypted backup file any time, protected with its own separate password.
• Backups are never uploaded anywhere; where you keep them is entirely up to you.
Encrypted, privacy-focused notes. Never touches a server. Stays on device.