Do you know any good tools to support the translation of .arb files?
It's a standard for Flutter and since Google Translator Toolkit will be sunset soon (https://support.google.com/translatortoolkit/answer/9462068) we're searching for a good solution to translate/gather our translations
Edit (June 2020): There's great new open source project called Arbify. This is a self-hosted tool to manage multiple translation projects focused on Flutter. You can edit arb files and fetch them via Dart package tool.
Aside from that some services like POEditor have announced basic support for ARB too.
At the moment the best support for arb files is on Localizely. However, this is a paid service and has strict limits on a free version. It allows to export arb translation files with plurals and placeholder support. It doesn't support genders, though.
There is also one simple web editor and one desktop editor (Babel) that support arb files.