This is how GCD looks like. Inner circle is gcd bar, outer one is cast bar.
Mouse cursor would be in the middle of it.
To move the icons around, click the "Unlock Icons" button in the options menu. When you are down, rightclick the red thingy.
Description
GCD is an addon that provides a cast bar, global cooldown bar, swing timer and cooldown timers in a circular fashion around the mouse cursor or alternatively at a fixed position on the screen.
If you find a bug or have any wishes for the addon feel free to write a ticket.
Keep in mind that a lot of addons mess with the default castbar.
Should the toggle for it not work properly its most likely that another addon modifies it as well.
To open the options menu type "/gcd"
The GCD Team
