This article describes how to change the language on Firefox OS.
The Marketplace is a store that features apps designed for any device that runs Firefox OS, Firefox for Android or Firefox desktop.
WhatsApp isn't directly available on Firefox OS, but you can still use a WhatsApp client on your device or chat with friends using Facebook or LINE.
You can install apps on your phone using either the Firefox marketplace or the adaptive app discovery engine. Follow the help topics below to get started.