This article broadly describes the analysis, design and development of the system utilitarian, called “Reading and billing calculation site through mobile devices.” The application is oriented Public Services Companies, first water services, to perform part of the billing process “in place” through phones or any mobile devices compatible with Android. Will enable you to take readings of service consumption, recording new gauging, online update and control the information for users and turnover. This technology is considered as such one site billing method as through Internet is connected with the database of the company, sending and receiving date information, which makes the calculation of the billing for the reading period, bringing benefits to the client and the service generating company.