Have unity run in the background?

Is it at all possible to make unity run in the background, not like when unity loses focus.
Like with steam, how you can close the window but it will still be there in the hidden icons list on windows.
Is it possible to achieve this with unity? Just want to run a timer but dont want the window to clutter up my alt tab screen.

I have found this: How to minimize unity3d application to tray? - Questions & Answers - Unity Discussions.