Note: I haven't updated Tracer for WoW 2.0.
This is a helper addon to log debugging messages to a SavedVariables file, which can be returned to the mod author so he/she can figure out what's going wrong with his/her addon out in the wild.
Gripping stuff. It's the only one of my posted addons to receive absolutely zero comments. Even I've never used it.
Please find it here.