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I use VSCodium. I use the extensions Dart and Flutter. The Dart one has an auto-formatter. Please use this setup to prevent unnecessary formatting changes.
If you've inherited this project, keep in mind that there are some python scripts in scripts/ that process translated strings for both website and app.
To compile translations run dart run build_runner build
Weblate: https://hosted.weblate.org/projects/simplytranslate-mobile/