Helps you not screwing up your Heroism ability. You will get a new action button that indicates whether all of your group, just some people or nobody has the Heroism debuff. If everybody has the debuff the button will be red and unclickable. If somebody has the debuff the button will be yellow and clickable (because you might want to press Heroism for the people that do not have the debuff (i.e. they died in a boss fight))! If nobody in your group has the debuff the button will be green and clickable. If you click the button your character will cast the class specific Heroism ability.
This addon is helpful for time sensitive situations (i.e. challenge mode), where you need to cast your Heroism ability a second time as soon as it is possible. As the cooldown on the ability is 5min and the debuff lasts for 10min, the player might accidentally cast the Heroism ability to soon and the cast has no effect. Also the player then has a 5min cooldown again, which is not good.
Currently only Mage and Shaman classes are supported (Hunter pets or Drums of Rage are not supported, yet)