Update for iPhone and Android users is announced by WhatsApp

With a game-changing update, WhatsApp now lets users sign in to up to four cellphones at once using the same account.
The change follows a flurry of demands from users of WhatsApp on various devices.
Mark Zuckerberg, the CEO of Facebook, announced the change in a statement on Tuesday. “Starting today, you can log into the same WhatsApp account on up to four phones,” he wrote.
As users will be able to use the same WhatsApp account on both devices, the new functionality will be especially helpful for people who have both a personal and a professional phone.