This addon is a plugin. You need to extract it to your /plugins folder to install it.
Allows users to Report Comments for moderation. If a report threshold (configurable) is exceeded for a Comment then that Comment is deleted, and if that Comment is the first in a Discussion then the Discussion is also deleted. This is a form of community moderation.
Users with sufficient privilages can review reported Comments and either clear or confirm the Reports with the latter resulting in the Comment being deleted.