In the multi language demo of QCMagritte, a magritte visitor is used that changes all label:, checkboxLabel:, comment: and group: sends in descriptions to automatically use a multilanguagestring. The parameter is used as the key. All unique keys are collected. The default translation is the key. That is used for missing translations.
Languages can be added on the fly. The demo has a simple UI to directly add and change translations. The whole translation table can be written to csv, and read back. This is not shown in the video Stephan Verstuurd vanaf mijn iPhone