In fact, WhatsApp video calling feature is not in the main build yet but it has finally shown up in the beta version on Android devices. I think in 2-3 months it will be available.
Meanwhile, Round Entertainment announced the Booyah that would interface with Whatsapp, Viber, Messenger, Messages, Gmail and so on.
You can add friends with select app , this will send a link to your friend and your friend will join to the video call. It supports for a group chat up to 12 participants
App Store link
