One of the best built-in features of the iPhone 4 is FaceTime, the video calling feature that lets you see who you are talking to by using the cameras on both phones. But it only works over WiFi and if both callers own an iPhone 4. Perhaps those limitations are why an app called Tango is the seventh most popular social networking app right now (iTunes link).
Tango lets you make video calls not just on iPhones but also on Android phones, and it works over 3G data networks as well. It works on both the iPhone 4 and the 3GS, and even iPod Touches. It’s been growing like crazy on both iOS and Android devices, adding one million downloads every two weeks. In the past three months, it’s grown from about 1 million downloads to 8 million (see chart. Of those, 7.2 million became registered users, and 42 percent (or about 3 million) have made a video call in the last 30 days.
Tango provided us with some other stats on its usage and growth as well. About 2.6 million people downloaded the app as a result of a direct invitation, with 45 percent of invites resulting in a download. The average length of a video call is 4 minutes. Downloads are split evenly between iOS and Android, and 60 percent of calls are over 3G or 4G data networks instead of WiFi. (Are you listening Apple/AT&T/Verizon?) Although the U.S. is the single largest country for Tango, the majority of members (55 percent) live outside the U.S. And half of the top 10 countries (South Korea, Hong Kong, Japan, Taiwan, and Singapore ) are in Asia.