Demo Instructions

Live demo: https://invoicego-demo-beryl.vercel.app
No login needed. The app has no accounts, so there is no email or password to enter. All data stays on the device (in the web demo: in your browser).
To see the app filled with sample clients, items, invoices and estimates, open Settings > Load demo data.
The web demo shows the whole interface. Sharing and printing PDFs, picking a logo from the gallery and saving backup files work best in the Android and iOS builds.

InvoiceGo is a complete, ready-to-publish Flutter app for freelancers and small businesses. Create invoices and estimates with line items, taxes, discounts and shipping, record full or partial payments, turn an estimate into an invoice with one tap, and share or print a clean PDF in two templates. Everything is stored on the device, so there is no server, no account and no monthly cost. The app has no push notifications or reminders.

Features

Invoices and estimates with line items, quantity, unit price, per-line tax, percent or fixed discount and shipping
Notes, terms and due dates with quick payment-term chips (Net 7, 14, 30, 60)
Automatic numbering with your own prefix (INV-0001 and EST-0001)
Convert an estimate to an invoice
Status tracking: draft, sent, partly paid, paid and overdue (overdue is worked out from the due date)
Record full or partial payments
Dashboard with outstanding, overdue and paid-this-month totals
Clients and items/services catalog with search
Invoice and estimate lists with search, status filters and sorting (newest, oldest, amount, due date)
Business profile with your logo, picked from the gallery
PDF export in two templates (Classic and Modern): share or print
40+ currencies and 5 number formats; number input follows the chosen format
Backup and restore to a JSON file, demo data loader and reset
Light and dark theme, 3-slide onboarding and a settings screen
Works fully offline: no server, no account, no ads and no tracking
Exact integer money math (no floating-point rounding errors), covered by unit tests

Easy to reskin

App name, colors and defaults live in one config file (lib/config/app_config.dart)
All on-screen texts live in one strings file (lib/config/strings.dart)
Artwork (logo, onboarding and empty-state pictures) is included in assets/images
Launcher icons for Android, iOS and web are already generated
Clean, commented code using Provider for state management

What is included in the download

Full Flutter source code (Android, iOS and web projects)
Buyer guide in documentation/index.html with pictures of the main screens: installation, running, renaming the app and package id, reskinning, editing texts, Android and iOS signing, splash screens, launcher icons, FAQ and third-party credits
android/key.properties.example showing how to set up your own signing key
Test suite: 85 automated unit and widget tests (money math, totals, tax, discounts, numbering, formatting, PDF building, backup and restore)
Artwork (app icon, logo, onboarding and empty-state pictures), README and changelog

Requirements

Flutter 3.41 or newer (Dart 3.11 or newer)
Android Studio or VS Code with the Flutter plugin
Android: SDK Platform 36 (compileSdk 36, targetSdk 36); the app runs on Android 7.0 or newer (minSdk 24)
For iOS builds: a Mac with Xcode and an Apple developer account
For Android release builds: your own signing keystore (the guide shows how to create one)

Not included

No signing keys or keystores (you create your own)
No backend, cloud sync, user accounts or multi-device sync: data stays on the device
No online payments or payment gateway: payments are recorded by hand
No push notifications or payment reminders
No Google Play or App Store accounts, and no publishing service
No ready-made signed APK or IPA files

AI disclosure

Code and documentation: AI-assisted tools helped write the code and the documentation.
Graphics: the app icon, logo, onboarding and empty-state pictures were made with AI image tools.
Review and testing: the author reviewed and tested everything. The project includes 85 automated unit and widget tests. The app has not been run on every device and OS version, so please test it on your own devices before you publish.

Credits

Open-source Flutter packages from pub.dev, each under its own licence: provider (MIT), shared_preferences (BSD-3-Clause), intl (BSD-3-Clause), pdf (Apache-2.0), printing (Apache-2.0; on the web it loads the pdf.js viewer, Apache-2.0), image_picker (BSD-3-Clause / Apache-2.0), file_picker (MIT), share_plus (BSD-3-Clause), cupertino_icons (MIT), image (MIT). Dev only: flutter_launcher_icons (MIT), flutter_lints (BSD-3-Clause). Flutter SDK and Material Icons (BSD-3-Clause / Apache-2.0). No font files are bundled: the app uses the platform font and PDFs use the standard PDF Helvetica font. The full list is in the documentation.

Changelog

Version 1.0.0 – First release: business profile and logo, clients and items catalog, invoices and estimates, automatic numbering, estimate-to-invoice conversion, statuses and partial payments, dashboard totals, PDF export in two templates, 40+ currencies, backup and restore, demo data, light and dark theme, onboarding, settings, and unit tests.

InvoiceGo | Flutter Invoice and Estimate App (Android, iOS, Web, Offline)