Vonage has updated both its Android and iOS apps with “free” video calling over both Wi-Fi and mobile data.  Although the video calls are limited to other Vonage users, the company is hoping to pull people away from its main competitor, Skype.  To that end, the app lets you invite your address book contacts and Facebook friends to download the app.

With Vonage’s new video calling feature, you can choose to display either your front or rear camera, and switch between the two during a call to let you show off what is going on around you.  While in a call you can also seamlessly switch between a video and just audio — a rather unique feature for video calling apps.

Other app features include:

– In-app purchase of long-distance calling credits
– Seamless use of existing mobile phone identity and contact list
– Hands-free calling using Bluetooth
– Ability to use Wi-Fi and 3G/4G wireless data networks worldwide
– Limited-time free calling to phone numbers in the United States, Canada and Puerto Rico

Like Skype, Vonage offers international long-distance calling to landline and mobile phones in more than 200 countries, but Vonage touts rates that it claims are 30 percent less than Skype’s pay-per-minute rates, on average.  The app works on devices running Android 2.3 and up, and iOS devices (iPhone, iPod touch, and iPad).  For more information see vonagemobile.com.