Hello. The plugin causes Joomla! to display an error page ("Error 0: Call to a member function isEnable() on boolean") if you try to access a page with any Fox Contact form protected by reCaptcha field BUT with Joomla!'s reCaptcha plugin being unpublished.
Not really a gamebreaker but I expected forms to just display broken captcha fields the same way it works with incorrect domain key and so on.