Mood Cairns

A private, fully offline Android mood tracker. Log how you're feeling against your own Scales, with your own Tags, in your own time windows, on your own device. Nothing is ever uploaded - backup, if you want it, is done your own way (hint: Syncthing works well on the encrypted backups you save.).

Features

• Custom Scales. Five built-in scales (Happiness, Anxiety, Stress, Boredom, Pain), each numeric and color-tagged. Add your own; archive the ones you don't want.
• Custom Tags. Choose from many built-in Tags for Places, People, Activities, Moods, etc. or add your own to customize your tracking!
• Prompt windows. Define time-of-day windows (e.g. morning 08:00-12:00, evening 18:00-20:00). The app fires one notification per window per day. Tap the notification to jump straight to the log entry screen.
• History and charts. Browse past entries, see per-scale trends over time.
• In your language. Available in English, Spanish, and German. Choose the app language in Settings, independent of your phone's language.
• Encrypted on-disk storage. The mood database is encrypted at rest using SQLCipher. The key lives in memory only while the app is unlocked, and is wiped when you lock it.
• PIN + biometric lock. PIN-gated app entry, with optional biometric unlock. PIN is hashed with PBKDF2-HMAC-SHA256 (600k iterations) before being stored.
• Encrypted backups. Manual export writes an AES-GCM-encrypted JSON file to Documents/MoodCairns/. The encryption key is derived from a backup passphrase you choose (minimum 8 characters) with PBKDF2-HMAC-SHA256 (600k iterations) and a fresh per-backup salt embedded in the envelope, so any install (including a fresh one) can decrypt with the same passphrase. Backups from older versions, which were encrypted with the app PIN, still import with that PIN.

Privacy contract

The app declares no network permissions. Without internet, the process literally cannot open a socket, which makes phone-home impossible regardless of what any included library tries to do.
The build enforces this, so a network permission can never be silently introduced by a dependency update.
If you want backups synced off-device, point Syncthing (or any file manager that can sync a folder) at Documents/MoodCairns/.

Contact

The best way to get in touch for issues, feature requests, etc. is the Issues page on github.com/lcdcode/mood-cairns. I will usually respond within 3 business days.

Source

Fully open source under GPL-3.0-only. Built on Kotlin, Jetpack Compose, Room, SQLCipher, and AndroidX.