WeChat, founded by Tencent Holdings, is China's most popular messaging application with over one billion monthly active users. It also functions as a super-application with social media, mobile payment (i.e. WeChat Pay), and other functionalities. Strictly speaking, "Weixin" refers to the domestic mainland China version of the application while "WeChat" refers to the version used overseas. The two are considered to be separate legal entities and there are some differences in terms of the functionalities available across the two versions as a result of the regulatory differences between China and abroad, although the two terms are frequently used interchangeably. We use the terms Weixin and WeChat interchangeably in our articles unless explicitly stated.