I should say the most popular Mobile Application in China would be “WeChat”. It has so many functions. Not only can you send voice messages to your contacts, also can post pictures or texts at the “Moments” section. Most importantly the app is totally free which intrigues so many debations among different parties.
The UI of this App is really user friendly. Although it has so many amzing functions, it arranges different sections so efficiently that people could figure out how to “master” it easily.