Smartphones and tablets are present in our everyday life. They emerged as an enter-taining device but nowadays mobile devices also getting more and more important forbusiness uses. Their big advantage is the light weight and small dimensions. They canbe easily used in a train or bus - difficult to imagine with a desktop pc or even a laptop.With business apps employees can do their work in office or out of office.This thesis deals with the modernization of the order-management system from K-Con. The modernization includes the development of an mobile web application whichenables agents to access order-data by smartphone or tablet.The heart of the new order-management-system is a RESTful webservice implementedwith the Web API technology. This services provides SSL-encrypted read- and write-access to the order data which are stored in a MSSQL-database. The web-applicationusing this web-service is build with the ASP.NET MVC5 framework and jQueryMobile.An UI-prototype for an desktop application collaborating with the new web-service hasbeen finalized. An agile process approach and prototyping has been used to develop an application that meets K-Con´s requirements.