Slack App-in-Tab Reborn by Axel Leroy

Slack App-in-Tab Reborn is a fork of "Slack App-in-Tab" which has unfortunately stopped working. This version keeps the same functionality as the original.

How to use

1. Install the extension
2. Visit https://app.slack.com and log into any of your workspaces
3. That's it, all your workspaces appear in the sidebar, just like in the Slack App

How does it work?

Slack App-in-Tab Reborn changes how Firefox presents itself to Slack so it believes you are browsing from a Chromebook. Since Chromebooks can't run the Slack app, it then shows the workspace switcher as it does in the app.