WhatsApp developers seem to be very busy as they are updating their app every day. WhatsApp officially announced Video Calling support which was one of the most requested features for this app and after that, we are getting Beta update almost every single day. Maybe they are fixing every possible bugs. The video calling will support the Android devices running on Jelly Bean 4.1 or up.
If you want to try out the latest WhatsApp Apk (2.16.359 beta) then just grab it from APKMirror or go to Google Play and update it.