Libraries Needed :
LibStub +
LibAddonMenuShowBlastbones
This addon will just display the blastbones icon grayed or not depending if you can use it surrounded by green or red (also depending if you can use it or not).
It will also display the maximum timer during which you will not be able to use blastbones again, so usually this timer will reset sooner to 0. Also when the timer will be at 0 it will blink for few seconds.
The only settings you have in option pannel is to unlock the icon to reposition it wherever you want on your screen.