Kaspersky Now is a Windows 8 Modern UI/ Metro app which provides a number of simple security functions (although it's not an antivirus tool itself).
If you have Kaspersky Internet Security 2013 or Kaspersky Anti-Virus 2013 installed, for instance, the program can use these to obtain and display your security status.
And you can also launch particular security functions (open the virtual keyboard at a click, say), or renew your Kaspersky licence.
Plus Kaspersky Now also displays the latest security news from the Kaspersky blog, so you can keep up-to-date with new threat trends.
This isn't exactly the most essential of security tools, then. But if you need a Metro front end for your existing Kaspersky tool then it may be useful (just about).