LanguageTrainer

A personal, ad-free Flutter app for drilling German vocabulary — noun articles (der / die / das) and verb conjugation (Präsens · Präteritum · Perfekt).

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Features

• Noun drill — tap the correct article (der / die / das)
• Verb conjugation drill — type the correct conjugated form
• Spaced repetition — SM-2 algorithm schedules cards by difficulty
• CEFR level filter — practice A1 through C2 words independently
• Category filter — focus on Nouns, Präsens, Präteritum, or Perfekt
• Gamification — earn XP per correct answer, level up, unlock achievement badges
• Adaptive shell — bottom nav on phone, navigation rail on tablet/desktop
• Offline & ad-free — all data stored locally with SQLite (Drift)

Vocabulary

Level	Nouns	Verbs
A1	60	30
A2	71	30+
B1	61	15+

Thematic groups include: everyday objects, family, travel, birthday, relationships, and abstract vocabulary.
Full word list with conjugation tables: docs/VOCABULARY.md

Platforms

Platform	CI build	Release artifact
Android	✓ debug APK	signed APK (if keystore secret set)
Linux	✓ .deb	.deb package
macOS	✓ .app.zip	ad-hoc signed .zip

Getting started

Prerequisites

• Flutter SDK stable channel
• Dart SDK ≥ 3.3.0

Run locally

cd src
flutter pub get
dart run build_runner build --delete-conflicting-outputs
flutter run

Run tests

cd src
flutter test

CI / CD

Push to main, develop, feature/**, or claude/** triggers:

1. flutter analyze --fatal-infos + flutter test
2. Debug builds for Android, Linux, macOS (artifacts uploaded for 14 days)
3. SBOM (CycloneDX JSON)

Pushing a tag v*.*.* triggers the release workflow and creates a GitHub Release with all three platform artifacts.

Android release signing

Set these four repository secrets to enable signed release APKs:

Secret	Value
ANDROID_RELEASE_KEYSTORE_B64	base64 -w0 release.keystore
ANDROID_KEYSTORE_PASSWORD	keystore password
ANDROID_KEY_ALIAS	key alias (e.g. languagetrainer)
ANDROID_KEY_PASSWORD	key password

macOS code signing (optional)

Secret	Value
MACOS_CERTIFICATE	base64 -w0 signing_cert.p12
MACOS_CERTIFICATE_PWD	.p12 certificate password

Without these secrets, the macOS build is produced without code signing (ad-hoc re-sign only).

Architecture

src/lib/
├── app.dart                      # AppServices container + MaterialApp
├── main.dart
├── data/
│   ├── nouns.dart                # ~215 nouns A1–B1
│   └── verbs.dart                # ~95 verbs A1–B1
├── models/                       # pure data classes + sealed QuizItem
├── services/
│   ├── database.dart             # Drift SQLite (3 tables)
│   ├── review_scheduler.dart     # SM-2 scheduling + level/category filters
│   ├── gamification_service.dart # XP, levels, achievements
│   └── sm2.dart                  # pure SM-2 algorithm
├── shell/                        # adaptive navigation shell (mobile / desktop)
└── screens/                      # Home · Quiz · Stats · Achievements · Settings · About

Full docs: docs/ARCHITECTURE.md · docs/REQUIREMENTS.md · docs/CLASS_DIAGRAM.md · docs/WIREFRAMES.md

License

See LICENSE.