Mobile Phone Barcode Scanning App

This is for a barcode scanning application that should utilise the phone camera. I require an application that will work on either of the below platforms (in order of preference). The initial application should support just one of the platforms listed. * iOS - iPhone, iPod Touch, iPad * Windows Phone 7.5 * Android - Samsung Galaxy S2, Tab 10.1 An end wish is to be able to have Multi Platform application that can support the above, although this is outside the scope of this work. I will prefer any suggestions to make this simple to port cross platform (e.g Phone Gap etc), though I am unsure if there will be any issues with the performance of the barcode reading using this. I am looking for the initital application for a proof of concept project. This will need to perform to the specification attached, but I am expecting to enhance the application further before full deployment. I need to keep the cost low on this initial project, the goal is to deliver a working proof of concept application to secure funding to then further develop the application.