Discord - Step up your game with a modern voice & text chat app. Crystal clear voice, multiple server and channel support, mobile apps, and more.
TeamLink - TeamLink is one of the leading and sumptuous solutions that is making web and video meetings extremely easy and efficient.
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.
Google Duo - Google's answer to Facetime, high-quality video calling on iOS and Android.
Around - Find people to hang out with.
Ripcord - A desktop chat client for Discord and Slack