Mood Cairns Mental Health app for Android description
A private, fully offline Android mood tracker. Log how you're feeling against your own scales, in your own time windows, on your own device. Nothing is ever uploaded - sync, if you want it, is your job (Syncthing works well on the encrypted backup folder).
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.
- 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 at a randomized time inside it. Tap the notification to jump straight to the log entry screen.
- History and charts. Browse past entries, see per-scale trends over time.
- 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 your PIN with PBKDF2-HMAC-SHA256 (200k iterations) and a fresh per-backup salt embedded in the envelope, so any install (including a fresh one) can decrypt with the same PIN.
- Home-screen widget for one-tap mood logging.
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/.
Source
Fully open source under GPL-3.0-only. Built on Kotlin, Jetpack Compose, Room, SQLCipher, and AndroidX.
