Oinkoin

Oinkoin is a privacy-first personal-finance tracker written in Flutter. Every expense, income, transfer, and recurring pattern lives in a local SQLite database (sqflite on mobile, sqflite_common_ffi on desktop) — the app never makes a network call, never asks for runtime permissions beyond biometric app-lock, and ships to Android, iOS, Linux, Windows, and macOS from a single Dart codebase. Android is the actively published target; iOS and desktop packages live in the tree but are not distributed.

Why it matters

• Offline by structure. ServiceConfig wires up only the local SQLite singleton (SqliteDatabase.instance, schema version 28), SharedPreferences, and the file system for backups. There is no telemetry endpoint in the runtime, so the privacy claim is architectural, not just policy.
• Real domain model. lib/models carries first-class types for Record, Category, Wallet, Profile, RecurrentRecordPattern, and tag associations. Wallet-to-wallet transfers store a separate transferValue so the same movement updates two wallets without double-counting in statistics; categories support emoji icons, custom colours, and a soft-archived state.
• Charts over the same model. community_charts_flutter powers the balance and per-category views; the statistics/ module exposes aggregated lists, balance charts, and CSV export built on top of the same Record type the UI uses.
• PRO as the funding model. The free build covers the daily-driver workflow; a paid unlock (also free on F-Droid) adds encrypted backup/restore (encrypt + crypto, AES-encrypted JSON written to /storage/emulated/0/Documents/oinkoin), recurring patterns, tags, and custom date ranges. Donations also go via Bitcoin, Monero, and Buy Me a Coffee.
• 24 locales. Translation files in assets/locales/ cover English, Italian, German, French, Spanish, both Portuguese variants, Russian, Arabic, Chinese, Turkish, Polish, and more, managed through i18n_extension.

How it works

lib/main.dart bootstraps timezone data, local_auth, package info, home-screen quick actions (add_expense / add_income), and a talker_flutter logger before handing off to lib/shell.dart. The shell is a bottom-nav scaffold with four per-tab navigators (Records, Categories, Wallets, Settings); each tab keeps a GlobalKey so quick actions and deep links can refresh the right state without rebuilding the tree.

SqliteDatabase is a singleton that opens movements.db at getDatabasesPath() on mobile and under the application documents directory on desktop, routing through SqliteMigrationService to bring older installs up to the current schema version. BackupService wraps that database in an AES-encrypted JSON envelope, and RecurrentRecordService materialises patterns into Record rows anchored to the pattern's original IANA timezone so DST shifts do not drift the recurrence.

Other dependencies that earn their place: intl for locale-aware currency rendering, share_plus for backup share sheets, emoji_picker_flutter for category icons, file_picker for imports, flutter_speed_dial for the add-record FAB, month_picker_dialog for stat drill-downs, flutter_colorpicker for categories, auto_size_text for dense tiles, and app_review_dialog for the gentle rating nudge.

Caveats

• Android-first distribution. Google Play ships the free build and the paid PRO build; F-Droid carries PRO for free but lags Play by a release or two. iOS, Linux, Windows, and macOS targets are in the repo but not published.
• PRO gates serious workflows. Backup/restore, recurring records, tags, and custom date ranges sit behind the paid unlock; either accept those gaps or pull F-Droid's free PRO build.
• Single-device by design. There is no cloud sync — backups are local JSON files (encrypted in PRO, plain in free).
• GPL-3.0 license. Forks must publish source modifications; fine for personal use, restrictive for closed-source redistribution.

Deployment notes

Download the latest APK from the GitHub releases page (built by the in-repo GitHub Actions workflows), install from Google Play, or grab PRO from F-Droid. Pairing the GitHub release URL with Obtainium gives self-updating installs.

git clone https://github.com/emavgl/oinkoin.git
cd oinkoin
flutter pub get
flutter run -d android      # or ios / linux / macos / windows

Schema changes go through SqliteMigrationService; if you fork, bump the static SqliteDatabase.version and add a migration step. The backup envelope is JSON containing categories, wallets, records, tags, and profile rows, optionally AES-encrypted with a user-supplied passphrase.