While Facebook continues its push into mobile, it may be surprising to learn that its popular mobile messaging service WhatsApp has released a desktop app for both Windows and Mac. “Like WhatsApp Web, our desktop app is simply an extension of your phone: the app mirrors conversations and messages from your mobile device,” explains the WhatsApp Blog. The ability to continue conversations that users “start on their phone even if they switch devices,” suggests Re/code, will prove “useful, and something that Google and Apple also allow with Hangouts and iMessage respectively.” Facebook paid $19 billion for WhatsApp two years ago. The service currently has about one billion users.