WhatsApp has been testing several new feature along the year and in the newest Beta, WhatsApp has made possible for message to send when the device is running flat or no network connection. A new WhatsApp feature will also allow one account to be logged in with 2 devices.
This opens possibility for WhatsApp account to be used on smartphone and tablet at the same time. However this is still in development and testing phase so there is no planned date on when will this be roll out to the public.
