It's FOSS shows you how to use the always on top feature in Linux.

Always on Top: An Often Ignored But Handy Feature in Linux Desktop - It's FOSS

With the "Always on Top" feature, you can keep an application on top of all other all the time. Comes in handy when you have to keep an app under watch.

Always on Top: An Often Ignored But Handy Feature in Linux Desktop - It's FOSS