WeChat is a mobile text and voice messaging communication service developed by Tencent in China, first released in January 2011. It is the largest standalone messaging app by monthly active users. The app is available on Android, iPhone, BlackBerry, Windows Phone and Symbian phones, and there are also Web-based and OS X clients but these require the user to have the app installed on a supported mobile phone for authentication. As of August 2014, WeChat has 438 million active users; with 70 million outside of China. Users can register WeChat with Facebook account or sign up with phone number. WeChat currently supports phone numbers of more than 100 countries to register. Registration cannot be done directly through Tencent QQ. But users can connect their WeChat account with Tencent QQ account after registering through phone number. WeChat provides text messaging, hold-to-talk voice messaging, broadcast messaging, sharing of photographs and videos, and location sharing.