What is it?
Fed up of "Who doesn't need this boss?" being met with silence or half the raid offering to sit, this is what this addon tries to address. Raiders can select a "desire" for each raid boss and then send that information (when in a raid). The raid leader(s) can see this information easily and change the group as required.
As well as the minimap icon you can open and close with /iwtb.
The options are in the interface->addons menu.
Double click title to minimise.
Possible additions (in no order):
Tool tips - for the <insult class of choice>.
Make group - rearrange the group with highest desire to criteria (tanks,healers,dps).
Sync guild rank(s) - only accept data from specific guild ranks (who cares about filthy casuals?).