Butter - Butter is a newly launched chatting application that focuses more on the privacy of its users.

Zulip - Chat for distributed teams. Zulip combines the immediacy of real-time chat with an email threading model. With Zulip, you can catch up on important conversations while ignoring irrelevant ones.

Whereby (formerly appear.in) - Collaborate from anywhere - video meetings with no downloads

Slack - A messaging app for teams who see through the Earth!

Zoom - Equip your team with tools designed to collaborate, connect, and engage with teammates and customers, no matter where you’re located, all in one platform.

Flow - Stop managing projects from your inbox.