WABetaInfo is a blog that tracks the development in Facebook-owned messaging App, WhatsApp. A few days ago they had tweeted mentioning the progress. They said that WhatsApp is running test-calls to see how things will work out in a multi-device system. Though, there is no word on the release date.

Multi-device support will give a new dimension to the App. As per the source, a WhatsApp user can use their account from four other devices, and it doesn't need to have an active Internet connection on their main device, unlike WhatsApp Web.

You can enable this feature by tapping, 'Link a New Device option' inserted in the App. There will be a toggle button for you to enable or disable any option.