I have a myspecialK one at the moment. There is always some sort of ad at the top, normally diet related e.g. weightwatchers etc. I thought they were just adverts that are paying the site 'minimins' to advertise. I could be completely wrong but on free forums like this, the people who maintain the website normally make their money this way rather than charge us a fee.
Any other type of downloader type applications on the screen are likely to be a virus.