Download prebuilt binaries here!
Flouze is an open source group expense tracker. Whenever you're traveling with other people, keeping track of who paid what and who owes whom quickly gets complicated. Flouze helps keeping a log of all expenses, which can be synchronized across several devices.
Another popular group expense tracking service supporting synchronization is Tricount which works really well but lacks the following features:
- History view of all changes to an expense log (for auditing/fixing mistakes)
- Monthly statistics (useful with long running accounts)
- Open protocol (although they do seem to have an API)
- Open Source (what is their app doing with my data?)
Another good open source alternative is Tricky Tripper, but it lacks proper support for synchronization.
Flouze is also an exercise in mixing Rust (for the logic) and Flutter (for the UI) in a mobile application.
Flouze is currently at an early stage of development, and supports the following features:
- Support several accounts (expense logs)
- Adding/editing/deleting Transactions
- Balance view showing who owes whom
- Synchronization (needs more testing)
The features currently being developed include:
- Statistics per day/week/month for long running accounts (eg. shared flat)
Rust and Flutter theoretically allow targeting both Android and iOS as mobile platforms. I currently only develop for Android. There's also a very basic CLI tool for interacting with Flouze accounts, that one should work on all desktop platforms.
The main parts of this repository are:
lib/the main Rust library holding all the shared logicflouze_flutter/a Flutter package exposing the Rust API to Flutter via Platform Channelsmobile/the (pure Dart/Flutter) sources of the mobile appcli/a simple CLI tool to interact with Flouze account files
The OpenSSL development headers are required for compilation to succeed, the
package is named openssl-devel on Fedora and libssl-dev on Debian
derivatives. Installing this package is only needed if you want to build the
flouze CLI for the host architecture, for cross compilation the build scripts
will take care of downloading and building OpenSSL for Android.
The Rust library needs to be cross-compiled for all supported Android targets
before building the mobile app. The generate-toolchains.sh script in
flouze_flutter/ needs to be run once to create standalone versions of the
toolchains contained in the Android NDK (which needs to be installed
beforehand). Once this is in place, the build-openssl.sh compiles OpenSSL for
various Android architectures, and the build-jni-libs.sh script in the same
directory builds the library for all targets.
After the native libraries are built, the following commands can be used
from the mobile/ folder to run/develop/debug the application:
# Get the dependencies
flutter packages get
# Generate the Dart files with language translations
./l10n-merge-translations.sh
# Run the code generation
flutter packages pub run build_runner buildThe synchronization server URL is configured by the mobile/assets/sync_server_uri.txt
file. The file should contain a URL in the form http://my.sync.server.tld:8080/.
Flouze ships with a basic built-in server, accessible via the serve command of
flouze-cli.
Sharing is accomplished by registering a URL prefix with the application, and
interpreting the URLs under that prefix in the app. The URL used for sharing
needs not match the actual address of the synchronization server, in other
words it is a "vanity" URL, which however needs to validate certain criteria
described in the Android Developer Documentation,
notably the hosting of a /.well-known/assetlinks.json file.
The URL of the sharing server is configured by the mobile/assets/share_server_uri.txt
file. The file should contain a URL of the form https://myapp.com/app.
With the example above, any link starting with https://myapp.com/app will
activate the mobile application. As of now, the only action using such links is
the cloning of a remote account. Clicking a link of the form
https://myapp.com/app/clone?accountId=[ACCOUNT_ID], where [ACCOUNT_ID] is
the UUID of the account, will activate the "Clone remote account" page of the
app. Remember, the server that will be contacted for the cloning is the
synchronization server, not the sharing server.
The mobile application can be configured to report crashes to Sentry (for now in
the Dart part only, the Rust part needs to be done). To do so, place your Sentry
DSN in mobile/assets/sentry_dsn.txt, and rebuild the application.
Flouze is using Dart's intl package for internationalization. The translations
are stored in ARB files in mobile/lib/l10n, those ARB files are edited using
CrowdIn and (at the moment) imported
manually into Git when changes happen. Contact me to get added to the project if
you want to add new languages.
Follow the official Flutter documentation
and add a key.properties file in mobile/android/.