Design and Read Webservice

Hello, We have developed a complete and functional web service in WCF(.Net) and have a developed a working android app with it. We now want to have a similar version for iOS . In this first phase, the main task is to simply communicate with our webservice(deployed through https) and display or send JSON data to it. A special focus is given to Design and the ability to communicate smoothly with our web service. We have mockups and clear technical specifications, we can also provide libraries and UI elements. Also as the app is in continuous development we will rehire you if this first version is satisfactory. This first simple project is urgent, as we want to evaluate the freelancer with whom we would like to work in future releases. Good Design, Quality and Commitment are a must.