Now call any phone number in the world from your Hangouts app using your data connection. Download and install the Hangouts Dialer to activate phone calling functionality in the Hangouts app. After installation, you can access all phone calling features directly from Hangouts or use Hangouts Dialer for a shortcut to the dialer screen in Hangouts.
в—Џ Make phone calls from the Hangouts app (and all calls to other Hangouts users are free!).
в—Џ Connect with your Google Voice number to make VOIP calls in the Hangouts app from your Google Voice number.
Notes: Mobile carrier and ISP charges may apply. Calls to Hangouts users are free, but other calls might come with a charge. View our calling rates at http://www.google.com/hangouts/rates.