WhatsApp just launched a new app — on desktop

Facebook is running to mobile. Except when it's not.

Facebook-owned WhatsApp, the mobile messaging service it paid $19 billion for two years ago, now has a desktop app, too.

Ironically, Facebook is running in the opposite direction, with the bulk of its business now coming from mobile. But there might be a good reason to further push WhatsApp, which has a billion users, onto people's desktops. (WhatsApp already offered a desktop feature, just not an app.)

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The key motivator: it allows people to continue conversations they start on their phone even if they switch devices. That's useful, and something that Google and Apple also allow with Hangouts and iMessage respectively.

The new app is available Tuesday for both Windows and Mac.

By Kurt Wagner, Recode.net.

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