The add-on allows guests to create threads/posts replies, and register after they have posted the content. This makes posting on your forums attractive, but handles spam message and invalid registrations automatically by periodically deleting all messages posted by guests, who did not end up registered on your site.
Admin Panel options page allows you to enable/disable posting of threads and replies. Guests see a constant message once they have posted a thread/reply asking them to register or login. If users login with an existing account, their content is automatically associated with their account and made visible. Users are redirected to their content immediately after logging-in. After successful registration, the content is associated with the new account, but it is not activated until users confirm their email/are approved by admins. If email confirmation and user moderation are disabled, the content is activated immediately, however, still following the rules of per-forum configuration - forums, which require new thread/new post moderation, will keep the content moderated.