Write an mobile application to redeem APP

We need an app to be created which will work on all popular devices (Iphone, android, windows mobile) The app will use API to our platform Voucher selling platform ( which will be built by us ) That app should be downloadable via google store / mac store on mobile device. Features / Pages are: Sign in to app ( using API call to our platform ) app will work only for logged in users who has created accounts on our web platform ) Forgotten password feature using existing API Once user is logged in the menu items will be: Find an order ( That will be search tool where you enter details like name / voucherCode or phone ) and it sends request to our existing API and displays results Order Details -> That's the page with some standard order details like name, price, etc Redeem a Voucher -> On order page you will see Redeem a voucher button, you enter that and you see a page where you confirm to redeem a voucher and redeem it. That sends API call to our platform and says back voucher has been redeemed. Some types of vouchers can be redeemed partially so that means you can redeem $30 , next time 60$ , etc.. so need small GUI to handle that on redeem a voucher page. Generally that's it, let us know approx costs and timeline and also what framework / language you will use to build such an App and i will feed in more details. Again, we will do the API - it's RESTful API, we just need someone with experience to build GUI which talks to our API and who's got experience in creating App available on google play / mac store / everywhere :) Happy bidding guys.