How To Pin Slack
This is how to get Slack to stay on one of your screens no matter which desktop you are on.
2.Next you have to minimise slack and make it small, so press Windows Key + Down. It should no look like this:
3.Next right click on the bar at the top and a drop down menu should appear like this:
4.You want to tick "Always on Visible Workspace".
Now when you change workspaces it should stay put.