Kallyas is strongly integrated with WPML plugin. To clarify, at this moment, Kallyas is translation-ready (can be translated) and WPML multilanguage-ready.

The language selector in the header will only be displayed if you have WPML plugin installed.

This plugin handles the multi lingual side of WordPress and unfortunately is commercial, but fortunately is the absolutely best plugin on the market for this task. This means you’ll need a separate license for WPML plugin as they don’t allow theme developers to include it or bundle with themes. If it were allowed we would’ve loved if we could bundle it, but sadly, we can’t. The investment however is great as it’s an unbelievable plugin.