It appears there is no Fish Extender group here on DISboards. There may be Fish Extender groups on other social media sites, but they are separate.
For those interested in starting one here, I've written a little informative post:
Setting up FE group
There's really no "rules" as to how a FE program runs. Basically someone maintains the list of those who wish to participate. The group can decide on what information is necessary to produce FE gifts. A basic list may only have DISname/room number/number of people in the room. A more involved list could be first & last names/ages/room number/favorite character/favorite color/allergies/whatever is deemed necessary to know. Also a decision can be made as to size of FE. Some groups break out the list(s) at 10-15 rooms max, so that there are multiple lists (and some people will participate in more than one list). Other groups just make one big list (upwards of 20-30 rooms).
At some point the list will "close". Typically this happens 30-45 days out from the cruise, so that everyone participating has time to organize/prepare their gifts. Shortly before this time (about 2-3 weeks prior) the organizer will either post the list (usually via a conversation is best, as that's more private), or directly on the Cruise Meet thread, to confirm everyone on it is still participating. It’s important to make a statement about "anyone not confirming by XX date will be dropped" at this time. A little harsh, yes, but often people will post on their cruise meet thread as soon as they book a cruise and say "I want to participate" and are never heard from again.
Once the list closes, the organizer will post the final list. Also, a decision must be made as to whether to allow late additions. Sometimes there is a "pixie dust" list. That is, basically, a latecomers list that gets posted about a week out from the cruise that others may or may not add to their "final" list. Be sure the "pixie dust" list participants realize they may or may not get gifts from others.
The other "biggie" is no other social media sites are allowed to be linked or search directions posted as to how find that other site here on DISboards.
OK, now that you have all met up on your Cruise Meet thread, and some people who have expressed an interest in participating in a Fish Extender exchange, it's up to one of you to be the contact point.
One note of importance, for those who wish to converse with each other (what Private Messaging is called here) you must have 10 posts to do so.