Also check Antwort, similar but seems to have better documentation and has been thoroughly tested: <a href="http://internations.github.io/antwort/" rel="nofollow">http://internations.github.io/antwort/</a>
The Ink Framework from Zurb has also got plenty of free templates that are thoroughly tested and responsive:<p><a href="http://zurb.com/ink/" rel="nofollow">http://zurb.com/ink/</a>