Messenger Video Calls - Facebook Messenger, now with HD video calls
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
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.
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
CallKite - Your website’s video call center in just one click.
Slack - A messaging app for teams who see through the Earth!