Microsoft’s Bing Conversational Understanding team has released a new reference app, the
MSDN Voice Search App, that demonstrates how to integrate your app into the new contextual voice capabilities available in Windows Phone 8.1.
The app itself is very simple and straight-forward, surfacing the MSDN documentation library from the Cortana experience. Once you have the app installed, ask ‘MSDN, what are universal Windows apps?’ while in Cortana and she’ll launch the MSDN Voice Search App and help you find an answer.
For more information, check out the Bing Dev blog
post on integrating Store Apps with Cortana (and don't forget to grab the app's source code). For more detailed WPDev 'how to', also check out the
Speech Dev Center and the recorded session from Build.