Previously, we reported that WhatsApp was developing a second version of the multi-device function. The team seems to have settled on a name called WhatsApp Companion that allows to you link a secondary device to your current WhatsApp account.
While this device has not been released yet, this means that you can use the same WhatsApp account on two devices at the same time. Do note that this is slightly different from using a smartphone and a desktop at the same time, but with two smartphones that are not possible at this moment.
From the screenshot, it's also mentioned that your current WhatsApp account will be logged out on your primary phone if you successfully link the secondary phone. However, that will only happen if you have two different WhatsApp accounts. Moreover, the linking will erase all locally stores messages and media files which can be backed up via Google Drive.
No testing has begun on iOS yet so this is only available on Android for now. Of course, iOS users will get to have it one day in the future. That's all we know for now. Stay tuned for more trending tech news at TechNave.com.