Windows 8 works exactly the same as Windows 7. But the icon has not gone into the collection you can't see, it has gome altogether. You can prove this by pressing Customise which shows all the icons. There are only two listed at this moment, and those are both visible. There should be 3.In Windows 7 you have to tell the OS to always show all icons for this RealTemp feature to work correctly. I haven't played with Windows 8 recently to see if anything has changed.
I just pressed Redraw Icons and now there are 3 visible and 6 listed! More and more confusing.
I set them all to Show, and I got 4. I exited them all. There are 2 left in the list, both shown as Show, but they are not visible.
I'll reboot and start again!