Develop app for Android & iPhone for Midtrade.net

We need an app developed for Android and Apple iOS. We already have the basic code on GitHub to work from to modify/ change. It was originally developed for iOS. You can look at the basic functionality of the website to get an idea of what is needed here- http://www.midtrade.net. We have created a basic functionality/ specifications document that is attached to this work project. After reviewing the functional spec, please give us an idea of time/ cost for a budget.