Activate WhatsApp Voice Call

How to Activate Whatsapp free calls Feature in your Android Phone:

> Install the latest whatsapp apk
> Open any Root Explorer (ES file explorer preferred ) and
  navigate to /data/data/com.whatsapp/shared_prefs/com.whatsapp_preferences.xml
> Add these 2 lines anywhere in the file but within the and save

Code:

<boolean name="call" value="true" />
<string name="call_allowed">all</string>

> Then go to Settings/Apps/Whatsapp and force stop it !
> Open the app again.

More Updates:
http://SwapnilTech.blogspot.com/2015/02/Whatsapp-Voice-Calling-Feature.html