Mobile development

I need an Android app. I would like it designed and built. I need an app designed similar to alipay or paytm. I do not need the additional in app features (such as taxi ordering and mobile credit recharge). Just the payment gateway, qr code scanning and api functionality so other websites/apps can use this gateway for payment. The app must not be tied to a bank interface. Instead it will use a virtual credit system. Users will buy credit from credit vendors such as gas stations and minimarts. For this reason there must be a credit vendor type of account which allows vendors to sell credit. The approval for such accounts will happen offline since physical contracts will be written. Credit venfors will take physical cash and the app must report how much money is to be collected from each credit vendor. We will need transaction histories for each vendor as well. Here is our revenue model: Users pay an additional 2% at the time of purchasing credit. So for example a user pays $102 and receives $100 worth of credit. The app will not be used for international purchases, only within a local context and one currency will be used. Users must be able to upload 3 photos on sign up. Proof of address, the front and back of their national ID card. Users must also be able to purchase credit from within the app using a credit card. Budget $3000 to $5000