The new CKEditor for WYSIWYG Module is great in its simplicity

I have now installed it on all my Drupal sites, how ever I wish to know how i can add spellcheck plugin. a feature often requested (and needed) by clients. I understand that this would not be something that would be featured in your module the same as the text-colour button and smileys. but i would simply like to know how to add these myself through a custom module to hook into your module.