Well there are 3 that i know of.
The first one was made before ECX came out. And the ECX team banned it with their code.
The second was made by encore after ECX came out but i have no clue where to get it.
The third was made yesterday ->
http://forum.esforces.com/showthread.php?p=928166#post928166
As for how it works. Read the readme ^^
Oh and if you install the third one. Dont folow the install instructions. ECX doesnt use pluggins.ini.
WIth ECX all AMXX pluggins are automatically loaded as soon as you drop the AMXX files into a certain directory. Not really sure what directory that is. But madman should know. So send him a PM or something ^^