The plugins are multi-language ready, but not all of them have much translations yet. However you can quite easily translate the plugins by yourself. The plugin decides based on the language setting of your WordPress site, which translation it will load.
An easy way to translate the plugin is by using special WordPress Plugin: Loco Translate. You can easily add new languages via this plugin.
By the way, I will gladly refund a part of the purchase costs via PayPal if you send the translation files afterwards so I can include it in the package for other customers.