Android based application

I need someone to design an android based application that will be installed on a tablet that will interact with a database from my Magento website. The idea is that the application will prompt the user for the amount of a bill, and then will scan a QR code attached to a customer ID from my magento Database, and will award points to the users account. The points program is already installed on my Magento website and will have to work together with the users account on my database. The application must also be able to redeem points. For example of the multiple uses: 1) User goes to a restaurant and makes a purchase, employee enters amount of bill into the tablet that will be installed at the cash register, and then the application will prompt the employee for the QR code of the customer. The tablet will scan the QR code and send the points to the database updating the users point balance. 2) The user comes to the restaurant and wants to redeem points. The employee chooses the redeem points option and scans the customers phone. The tbalet will display the points balance and financial equivalent. The employee will then enter the amount of the bill (or the amount of the points he wishes to use to receive a partial deduction on the bill) and this will subtract the points from the customer bill and send a email receipts to the employees email, the customers email, and my companies email. Then the system would deduct the points from the database, make a record of the transaction and update the balance of the users poitns in the database.