What drops <insert item>

[Vixxana]

I used to have a mod, awhile ago, not sure which one it was or if it came with a compilation I had or what but if I clicked a linked item or moused over something in my inventory, it would tell me what boss/instance it came from.

I've tried searching through categories but I'm a bit of a noob =/

Anyone know what mod I'm talking about and if so, where to get it?

Thanks in advance for any help with this =)