WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.
Slack Video Messaging by Standuply - Easily record and send video messages in Slack 📹
Quickie - 3-60 second video calls with your friends
Messenger Video Calls - Facebook Messenger, now with HD video calls
CallKite - Your website’s video call center in just one click.
Principle for Mac - Animate your ideas, design better apps