What is Country Info Sync?
Country Info Sync is an offline-first country information app built with Flutter. Open it with no internet connection and it still works: the app keeps a local copy of every country it has ever downloaded, and if that is empty it falls back to a dataset bundled inside the app itself. There is a three-tier data strategy — live API, then local cache, then bundled data — so the app is never a blank screen.
It is completely free and fully open source under the MIT licence. There are no advertisements,
no in-app purchases, no user accounts and no analytics. You can read the entire source code, fork
it, or build your own version with flutter build apk --release.
Features
- Country explorer. A scrollable list of every country with its flag, name and capital city.
- Smart search. Search by country name or capital city. Matching is case-insensitive and exact matches are sorted first.
- Favourites. Tap the heart on any country to save it. Favourites are stored locally and survive a full app restart, and there is a toggle to show only favourites.
- Compare two countries. Long-press up to two countries and open a side-by-side comparison of capital, population, area, continent, subregion, calling code, languages, currencies and timezones.
- Country details. A rich detail screen with an animated flag, native name and grouped sections for general information, communication data and full lists of languages, currencies and bordering countries.
- UNESCO World Heritage sites. Countries with curated data show their heritage sites with descriptions, loaded from an offline JSON file so no network is needed.
- Wikipedia summaries. An "About this country" card with a short summary and a link to the full article. Summaries are cached for offline reuse.
- Dark and light theme. Switch themes from the app bar; the choice is remembered across restarts.
- Adaptive layout. Spacing and typography scale with the screen, so the same code looks right on a small phone, a tablet and a desktop window.
See it in action
A 30-second tour of the app: browse the country list, search by name, save a favourite, open a country's details with its Wikipedia summary, and switch to dark mode.
Screenshots
Supported platforms
| Platform | Status |
|---|---|
| Android | Tested — requires Android 7.0 (API 24) or newer |
| iOS | Tested — iPhone and iPad |
| macOS | Tested — Apple Silicon |
| Web | Tested — Chrome, Firefox, Safari |
| Windows | Build available, untested |
| Linux | Build available, untested |
How to install
Android
Download the signed APK from the latest release and open it on your phone. You may need to allow installation from unknown sources, since the app is distributed directly rather than through a store.
Web
Nothing to install — open the web app in any modern browser.
Build it yourself
The project targets Flutter 3.47.2 and Dart 3.13.2. Clone the repository, run
flutter pub get, then flutter run.
Frequently asked questions
Is Country Info Sync really free?
Yes. It is free of charge and open source under the MIT licence. There are no ads, no subscriptions, no accounts and no data collection.
Does it work without an internet connection?
Yes. Country data is cached locally with Hive, and a bundled dataset is used as a final fallback, so the app works with zero connectivity.
Do I need an API key to run it?
No. All upstream services used by the app are open and keyless.
Which countries are covered?
Every country returned by the countries.dev dataset — around 250. UNESCO World Heritage entries are currently curated for a subset of countries and are being expanded.
Can I contribute?
Absolutely. Bug reports, feature requests and pull requests are welcome — see CONTRIBUTING.md.