Français · Deutsch · Español · العربية · 日本語 · 简体中文 · 繁體中文 · Português BR · Русский · Italiano · Nederlands · Polski · Українська · Türkçe · 한국어 · हिंदी · Svenska · Dansk · Norsk · Suomi · Čeština · Magyar · Română · Ελληνικά · Tiếng Việt · ภาษาไทย · Bahasa Indonesia · Bahasa Melayu · فارسی · עברית · Hrvatski · Български · Српски · Slovenčina · Català · Euskara · Galego · বাংলা · മലയാളം · தமிழ் · اردو
LUNA works 100% without internet. Your cycle data never leaves your device.
No account. No server. No third-party service. Not now, not ever.
| Guarantee | How it is enforced |
|---|---|
| Data stored on your phone only | Encrypted SQLCipher database on local storage. No sync to any server. |
| Works completely offline | Zero network calls. No API, no backend, no CDN. Install once, use forever without internet. |
| No account, no registration | Not even an email address. Open the app, set a PIN, done. |
| No dependency on any external service | No Firebase, no Google Analytics, no Mixpanel, no Sentry, no Amplitude, no Stripe, no third-party SDK of any kind. Zero. |
| AES-256-GCM encryption at rest | Your database is encrypted with a key derived from your PIN via Argon2id. The key never leaves the device. If someone steals your phone, they get an unreadable blob. |
| Encrypted optional backup | If you enable iCloud / Google Drive: the file sent to the cloud is an opaque ciphertext blob. Apple and Google cannot read it. We cannot read it. Nobody can except you. |
| Zero telemetry, zero analytics | No crash reports, no usage metrics, no feature flags, no A/B tests. Nothing. |
| Panic wipe in 3 seconds | Hold the panic button: database + salt + all cryptographic keys are destroyed irreversibly. |
| Fully open source | MIT / Apache-2.0. Every single line of code is public and auditable. |
| No server | We do not have one. There is no backend, no remote database, no API to call home. |
| No internet required | The app functions 100% offline. No internet connection is ever needed or used. |
| No account | No email, no password, no social login, no phone number, no identity verification. |
| No data sale | We cannot sell your data because we never receive it. It never leaves your device. |
| No ads | Zero advertising SDK, zero tracking pixel, zero user profiling, ever. |
| No push telemetry | Period reminders use the OS notification system only — no data passes through any server (ours or anyone else's). |
| No hidden SDK | The app binary contains only what you see in this repository. No hidden library, no obfuscated call, nothing. |
iOS: App Transport Security (ATS) enforced — no arbitrary network loads allowed
Android: android:networkSecurityConfig blocks ALL outbound connections at OS level
Rust: Cargo.toml has zero networking dependencies (no reqwest, no hyper, nothing)
Build: CI verifies cargo deny — any new network dep fails the build
The privacy is architectural. It is not a policy, a checkbox, or a promise.
It is physically impossible for this app to send your data anywhere.
| English | Francais | Deutsch | Espanol | Japanese |
|---|---|---|---|---|
 |
 |
 |
 |
 |
| English | Francais | Deutsch |
|---|---|---|
 |
 |
 |
| English | Francais | Deutsch |
|---|---|---|
 |
 |
 |
| English | Francais |
|---|---|
 |
 |
| English | Francais |
|---|---|
 |
 |
| English | Francais |
|---|---|
 |
 |
luna/
luna-core/ # Rust shared library (UniFFI bindings)
src/
api.rs # Public API: LunaEngine (open_vault, log_day, predict_next…)
vault/
crypto.rs # AES-256-GCM + Argon2id + HKDF-SHA256 + zeroize
database.rs # SQLCipher via rusqlite (bundled)
engine/
prediction.rs # Cycle prediction algorithm
types.rs # Cycle, DailyLog, Prediction, CycleSummary
tests/
behavior_tests.rs # 23 behavior tests (9 user journeys)
ios-app/ # SwiftUI (iOS 16+)
LunaApp/
LunaApp.swift # AppState, entry point
Views/ # HomeView, CalendarView, InsightsView…
ViewModels/ # HomeViewModel, InsightsViewModel
Resources/ # Localizable.xcstrings (6 languages)
android-app/ # Kotlin + Fragments (API 26+)
app/src/main/
kotlin/app/luna/
ui/ # Activities + Fragments
viewmodel/ # ViewModels (StateFlow)
services/ # KeystoreService, VaultService
res/ # Layouts + i18n strings (EN/FR/AR/HE)
scripts/ # Build scripts + CI helpers
build-ios.sh # Generates xcframework
build-android.sh # cargo-ndk → .so files
check_i18n.py # Checks translation completeness
| Layer | Technology |
|---|---|
| Shared core | Rust 1.93+ · UniFFI 0.28 (proc-macros) |
| Encryption | AES-256-GCM (aes-gcm) · Argon2id (argon2) · HKDF-SHA256 (ring) |
| Key hygiene | zeroize (memory zeroing on drop) · secrecy (SecretVec) |
| Database | SQLCipher via rusqlite (statically bundled — zero external dep) |
| iOS UI | SwiftUI 4 · Keychain · LocalAuthentication (Face ID / Touch ID) |
| Android UI | Kotlin · ViewBinding · Navigation Component · BiometricPrompt |
| iOS bindings | uniffi-bindgen-cli generate --language swift |
| Android bindings | uniffi-bindgen-cli generate --language kotlin + cargo-ndk |
LUNA uses a weighted exponential moving average over cycle history, as validated by:
- Apple Women's Health Study 2023 — largest prospective menstrual health cohort (>50,000 participants)
- Predictive modelling of menstrual cycles — ARIMA/LSTM models achieve 87-95% accuracy after 3+ cycles
- ACOG Practice Bulletin — normal cycle range 21-35 days, confirmed in population data
The prediction algorithm:
- Computes weighted average of recent cycle lengths (more recent = higher weight)
- Applies standard Bayesian confidence interval (±days shrinks with more cycles)
- Estimates fertile window as [ovulation-5, ovulation+1] (sperm survival window)
- Detects ovulation at ≈ cycle_length - 14 days (luteal phase is fixed ~14 days)
No pseudoscience, no moon cycles, no crystal healing.
# Rust toolchain
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup target add aarch64-apple-ios x86_64-apple-ios aarch64-apple-ios-sim
rustup target add aarch64-linux-android armv7-linux-androideabi x86_64-linux-android i686-linux-android
cargo install cargo-ndk uniffi-bindgen-clicd luna-core
cargo test # 32 tests (9 unit + 23 behavior)
cargo clippy -- -D warnings./scripts/build-ios.sh
# Opens Xcode: open ios-app/LunaApp.xcodeproj./scripts/build-android.sh
# Or: cd android-app && ./gradlew assembleDebugLUNA supports 40 languages:
| Tier | Languages |
|---|---|
| Tier 1 (full) | EN, FR, DE, ES, AR, JA, ZH-Hans, PT-BR |
| Tier 2 | IT, NL, PL, RU, UK, TR, KO, HI, SV, DA, NO, FI, CS, HU, RO, EL |
| Tier 3 | ZH-Hant, VI, TH, ID, MS, FA, HE, HR, BG, SR, SK, CA, EU, GL, BN, ML |
RTL languages (AR, HE, FA) are fully supported with mirrored layouts.
LUNA targets WCAG 2.2 Level AA:
- All tap targets ≥ 44pt / 48dp
- Full VoiceOver (iOS) and TalkBack (Android) support
- Dynamic Type / Font Scale support (up to 310%)
- Reduce Motion: all animations disabled
- High Contrast mode support
- Screen reader announcements for all critical actions
User PIN
Argon2id (64 MB, 3 iterations, 4 threads)
Master Key (256-bit)
HKDF-SHA256("db_key") SQLCipher database key
HKDF-SHA256("sync_key") AES-256-GCM backup encryption key
All key material: SecretVec<u8> (zeroized on Drop)
Database file: fully encrypted, secure_delete ON, WAL mode
Network: ZERO — android:networkSecurityConfig blocks all connections
Backup: encrypted blob — even cloud provider cannot read contents
Panic Wipe (3-second hold): deletes DB + salt + Keychain/Keystore entry. Irreversible.
See CONTRIBUTING.md.
Areas where contributions are especially welcome:
- Translation improvements (see
scripts/check_i18n.py) - Security audit of
luna-core/src/vault/ - Accessibility testing with real assistive technology
- BBT chart visualization
- HealthKit / Health Connect integration
Dual-licensed under MIT and Apache 2.0.
Copyright © 2026 LUNA contributors.
Note: This app does not provide medical advice. Always consult a healthcare professional for medical concerns related to your menstrual health.