Custom monitor apps instead of gnome system monitor in buttons

[ehheeh]

Has this issue been covered in the Wiki?

• [x] I have read the Wiki and my issue is not covered.

Is there an existing issue reported already?

• [x] I have searched the existing issues, it does not exist.

Describe the new feature you would like

being able to add like btop or other monitor apps in the middle button at menu would be cool