WeChat is the most popular mobile app in China. Unlike any other IM app, WeChat is an app which can do a lot of things. If you want to communicate with your clients in China, the best communication tool is WeChat.
As a Drupal-based web development agency and a remote team, we can not work without online tools. We found it is impossible to use only one tool to serve all purposes. So, We need to integrate several tools into our workflow. Each tool has its own purpose.