WhatsApp Calling feature that was launched few weeks back for Android has become one of the popular peer-to-peer calling apps available for mobile. While Skype, Viber and Line are still popular, WhatsApp’s growing subscriber base at more than 70 million users has made others app irrelevant in competition. The much awaited feature has now arrived for iOS users on the App Store. “WhatsApp Calling: Call your friends and family using WhatsApp for free, even if they’re in another country. WhatsApp calls use your phone’s Internet connection rather than your cellular plan’s voice minutes. Data charges may apply. Note: WhatsApp Calling is rolling out slowly over the next several weeks,” says the official app. So, in case the app is still not available for you, wait patiently since they have promised to roll out gradually for everyone soon. Now, head to the App Store and download the latest version of WhatsApp to check whether the update has been rolled out to you or not.