Following the development of electronic devices, mobile phone has been designed with more technological functions. Meanwhile, mobile applications are rapidly developed as well due to the demand of mobile phone users. Creative designing and Multi-function have become the main characteristic attracting more users. Taiwan Water Company started its water fee payment system on the mobile application since 2012. The application offers a more convenient online platform, on which users can inquire bill and pay water fees, to their customers. This study focuses on discussing the situation of the application using. We find that if a mobile application is able to enhance the efficiencies of operating and learning, the application can obtain positive reputation and will become more popular among users.