Voice search service 'Ok Google' can now be used by third-party apps

Google's voice search service can now be used on apps developed by third-party developers.

Ok Google is the voice search service of Google.

Apps like NPR One, TuneIn, Zillow, Flixster, TripAdvisor are enjoying early access to the Custom Voice Actions feature.

The service for now is limited to selected group of apps which include Flixster, Instacart, Lincoln, NPR One, Realtor.com, Shazam, TripAdvisor, Trulia, TuneIn Radio, Walmart, Wink, Zillow.

The voice commands are fairly restricted even within the apps that are supported.