There is a list of currently available addon packages here: http://www.composite.net/Add-on-Market/Packages
I don't think there is one with your specific needs, but I think it would be quite easy for you to create your own data type within composite and link up a form on a page that would save user provided messages. Then all you need to do is render out all the existing messages onto a page.
Learn more here: http://users.composite.net/Superuser/Data/A-Guide-to-Creating-Datatypes
I don't think there is one with your specific needs, but I think it would be quite easy for you to create your own data type within composite and link up a form on a page that would save user provided messages. Then all you need to do is render out all the existing messages onto a page.
Learn more here: http://users.composite.net/Superuser/Data/A-Guide-to-Creating-Datatypes