Developp a mobile application for different platform

I want to build a mobile apps of an existing platform for the different mobile device operating systems (a cross platform apps) :android, iOS app window and so on. The developed application will be uploaded on the different platform for download by the users at the end of the project. There is a reference mobile application from which our mobile apps will be inspired. The project have to be done with high quality in all the steps from UI design to the development. There is a server site with the web application, the mobile app will be linked this. We are bound by the datelines, therefore we will appreciate short and realistic datelines. We will like to work with in a structured manner:Mockup, design of the different pages, implementations of the different functionality and test. We appreciate high quality bid taking into account our requirements and our restricted financial resources. We have other project in the pipe and we are building a long term relationship starting with this project.