WhatsApp Desktop is the desktop client for WhatsApp Messenger, a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS. WhatsApp Messenger is available for iPhone, BlackBerry, Android, Windows Phone, and Nokia and yes, those phones can all message each other! Because WhatsApp Messenger uses the same internet data plan that you use for email and web browsing, there is no cost to message and stay in touch with your friends. In addition to basic messaging WhatsApp users can create groups, send each other unlimited images, video and audio media messages.
With WhatsApp on the desktop, you can seamlessly sync all of your chats to your computer so that you can chat on whatever device is most convenient for you.
Download: WhatsApp Desktop 0.3.4479