Descriptive Statistics

Description

A descriptive statistics calculator for students, published on the Play Store as Descriptive Statistics (com.neteru.tixtat). It is the Flutter rewrite of a legacy native Android app.

• Three calculators: discrete variables (Xi, Ni), continuous variables (classes [L1 ; L2[, Ni) and qualitative variables (modalities, effectifs).
• Entry: row by row, bulk import, or a raw series ("3 5 5 7 3") tallied into rows. For continuous variables, classes default to the Sturges rule.
• Results: frequency table, means, mode, median, quartiles, deciles, variance, standard deviation, covariance/correlation, coefficient of variation, with a step-by-step explanation of every calculation.
• Charts: bar, line and box plot (quantitative), bar and pie (qualitative), chosen in Settings.
• Backups: save a result, reopen it in its calculator, share it as text.
• Languages: French, English, German, Spanish, Portuguese. English is the fallback for other device languages.
• Privacy policy: bundled with the app, in Settings.

Screenshots

The Play Store images, in English; other languages are in store/screenshots/<lang>/.

Tech stack

• Flutter (stable channel), Dart SDK >=3.8.0 <4.0.0
• State: Riverpod with code generation (riverpod_generator)
• Routing: go_router
• Storage: Hive CE (backups) + SharedPreferences (settings)
• i18n: Slang
• Charts: fl_chart (the box plot is a CustomPainter)
• Android build: Gradle 9.3.1, AGP 9.1.0, Kotlin 2.4.0, Java 17

Installation

cp .env.example .env
flutter pub get
dart run slang
dart run build_runner build --delete-conflicting-outputs
flutter run

Environment variables

.env is bundled as an asset, so everything in it is public. It only holds the theme colors:

Variable	Description	Example
APP_PRIMARY_COLOR	Primary theme color, hex	#353839
APP_SECONDARY_COLOR	Secondary theme color, hex	#009ee3
APP_ACCENT_COLOR	Accent theme color, hex	#f5f5f5

Running tests

flutter test
# with coverage, as run in CI:
flutter test --coverage

Unit and widget tests live under test/, mirroring lib/. Infrastructure singletons are mocked with mocktail through a GetIt test-locator override (test/helpers/test_utils.dart).

Architecture

• lib/main.dart: entry point.
• lib/core/bootstrap/app_bootstrap.dart: env, Hive, DI and locale setup.
• lib/app.dart: root widget, theme and router.
• lib/core/stats/: the calculations, as pure functions (computeDiscreteStats, computeContinuousStats, computeQualitativeStats, raw-series grouping). They have no Flutter dependency and are the most heavily tested part.
• lib/core/providers/: Riverpod providers (calculator entry state, settings, home tab).
• lib/core/data/backups/: saved results (Hive).
• lib/view/screens/: calculators, backups, documentation, tutorial, settings, onboarding.
• lib/view/components/calculators/: entry form, dialogs, stats table, explanations, charts.

Generated files (*.g.dart, locator.config.dart) are not committed; rebuild them with dart run slang and dart run build_runner build.

Quality

dart format .
flutter analyze
flutter test

Privacy policy

The privacy policy ships in the app (assets/docs/<locale>/privacy_policy.html, one per app language, opened from Settings). The store listings link to the public copy at https://netersoft.github.io/descriptive-statistics/privacy/ (English: /en/), served by GitHub Pages from the public netersoft/netersoft.github.io repository. After editing the policy, regenerate the pages and push that repository:

python3 tool/build_privacy_pages.py ~/Dev/Projects/Web/netersoft.github.io

Release

1. Bump version in pubspec.yaml (on a branch + PR).

2. Build the App Bundle with the release keystore (android/key.properties, never committed):

   flutter build appbundle --release --flavor prod

3. Upload build/app/outputs/bundle/prodRelease/app-prod-release.aab to the Play Console.

CI (.github/workflows/flutter.yml) runs formatting, analysis, tests and a coverage floor on every PR and push to master. On v* tags or a manual dispatch, it also builds a release APK (debug-signed, for QA only) and an unsigned iOS build. Nothing is published to a store.

Build flavors

dev, staging and prod only change the app identity (applicationId suffix and name), so they can be installed side by side:

flutter run --flavor dev

iOS has no flavor schemes; build it without --flavor.

Contacts

• Maintainer: Noé Gnanih (@noeGnh)

License

Descriptive Statistics is free software by Netersoft.

• Code: the source code (lib/, test/, tool/ and the platform folders) is licensed under the GNU General Public License v3.0.
• Content: the texts, translations and pictures made by Netersoft for the app are licensed under Creative Commons Attribution-ShareAlike 4.0.
• Third-party files keep their own licenses: the Montserrat, Open Sans and Noto Sans Greek fonts (SIL Open Font License 1.1, assets/fonts/*/OFL.txt), and the KaTeX fonts that flutter_math_fork renders the course formulas with (MIT, assets/licenses/katex_fonts.txt, registered in the app's license list at startup).
• Names and icons: the Netersoft name, the app names (Descriptive Statistics, Statistique Descriptive, Deskriptive Statistik, Estadística Descriptiva, Estatística Descritiva), and the app icons and logos (assets/images/launcher/) are not covered by these licenses. A modified version must use another name and icon.

Copyright © 2018-2026 Netersoft.