https://techcrunch.com/2018/02/28/hangout-chat-googles-slack-competitor-comes-out-of-beta/

Hangouts Chat, Google’s take on modern workplace communication, is now generally available and is becoming a core part of G Suite. Hangouts Chat was first announced at Google I/O 2017, together with Hangouts Meet. While Meet went right into public availability, though, Chat went into an invite-only preview. Now, Google is rolling Chat out to all G Suite users over the course of the next seven days.

For all intents and purposes, Hangouts Chat is Google’s take on Slack, Microsoft Teams and similar projects. Since Google first announced this project, Atlassian also joined the fray with the launch of Stride. Like its competitors, Chat is available on iOS, Android and the web.