WhatsApp is working on a function that will allow you to link a secondary mobile device to your WhatsApp account without requiring an active Internet connection on the main device in order to send messages. The chats will automatically sync across both devices.

The "companion mode" function was discovered last year in the WhatsApp beta for Android 2.22.15.13 update.

According to WABetaInfo, the companion mode has been released to all beta testers who install the latest version of WhatsApp beta for Android available on the Google Play Store.

SEE MORE