WhatsApp Video Call application is the one that enables you to make video calls to any WhatsApp client.
WhatsApp video calls are compatible with Android 4.1 and higher operating system versions.
Before starting the video call or receiving it, it is very important that you have a strong internet connection because a weak or poorly configured connection could worsen the quality of the audio or video.
If you are connected to a Wi-Fi network the quality of the video call will depend on the signal quality and speed of your network.
To make a video call, open a chat and tap the icon of the camcorder in the upper right of the screen.
When you receive a video call, you’ll see the incoming video call notification on your handset screen.
To answer, slide the green answer button to the right. If you do not want to answer only you will have to slide the red reject button to the left.
If you want to reject a video call with a message you only have to press the message icon and select one from the list.
Find out more about WhatsApp Video Calls at: iPhone or Windows Phone