The FooEvents plugins come bundled with translations for several popular languages and locales which are listed here:
You can modify the bundled translations or create your own custom language files using a free software application called Poedit.
The instructions for creating custom language files and uploading them to your site can be found in this help article:
FooEvents is also compatible with the WordPress Multilingual (WPML) plugin which makes it easy to create multilingual websites.
The FooEvents Check-ins app can be used in the following languages: