Trying To Find an Add-On

Let me try to describe this... sad thing I just came across it about an hour ago and now can't find it. One of those things where I think mental note "Go back to that" and forgot. Now can't find it anywhere, don't remember developer or even really what to call it.

So I have seen it on other people's forums as well... and you can set like pop up bubbles (boxes) that you can input like "log in now to view this thread and post HERE first" where thread and here are linked. But you can make custom messages that show up to guests, or new users, etc.