Slack's new feature -- or old feature, if you used AOL Instant Messenger anytime since the late nineties -- offers five default statuses for situations like "In a meeting" or "Out sick," but of course you can also set a custom status with more personal detail and wit if that's your thing. Every status also includes an emoji you can use to properly convey what's taking your attention away from the chat itself, and if you don't pick an emoji you'll get defaulted to the speech ballon. In the chat window and the left sidebar, only the emoji will show up next to your name, but hovering or tapping it will bring up your full away message. In the browser or on the desktop, you simply click your name in the upper left corner to set a status. On the mobile app, statuses are tucked inside the "More items" menu at the top right.
Finally, since Slack likes to play nice with third-party apps, those can also set your status for you without any work on your part. If you're on a voice or video call within Slack, your status will update accordingly and apps like Zenefits or Meekan's scheduling assistant can even set your status when you're taking time off or have a meeting blocked on your calendar.
According to Slack, status updates are rolling out to users over the next few days, but you'll need to download the latest versions of the desktop and mobile apps to get it.