Online vouchers system with app run by SIM modem gateway support HTTP USSD for TOP UP

Greetings. I am in need of a php and MySQL developer which can use a responsive designed which we'll provide (for the user interface) and GSM Gateways API to develop a USSD based platform for SIM card manipulation in the GSM Gateway. Developed with latest version of PHP. Required is website and app on apple store and google play? Complete system whereby it has control panel which you can upload all vouchers to. I.e.: google play voucher, apple, amazon, network vouchers. and many more. vouchers to be uploaded in bulk and sorted automatically. Txt format, or added manually! - add retailers by creating an account for them, they can then buy vouchers at a set price and sell it to a customer in their store, also print them using a POS system. - Send reminders and notifications to app/email to retailers’ accounts when balance is running low, or when they haven’t viewed their statement and many more. - Admin will add credit to each account manually. The balance will then be visible to the retailers account with time and date. Each transaction requested by the retailer to be recorded, history of every transaction is sold and printed. - Using USSD to top up another mobile number remotely, send inquiries, etc/ App will talk to the server to make these requests. - Sim server which can be used as follow : [login to view URL] - [login to view URL] - Security level when logging in to the account needs to be supported by 2FA authentication. And other security measures, Register IP and location, and record of each log in details which can be seen by the user and the admin. - Display has to be set in two languages (Arabic or English language). - Only allow voucher codes to be seen once printed. - User can change he’s password. However any other changes to the account needs to be requested and verified by the admin. - Be able to send and receive messages from admin. - Admin to send bulk notification and messages to all users. - Advert page (pop up images or texts by admin) visible on app. - Limit user access to different modules. - We need a very good Java programmer who can work with AT commands in Modem. Clearly, the developer need to develop a java program which can pull request from mySql table . The request will Contain phone number and recharge amount. Based on the phone number (which also tells who the Gsm Carrier is) the program will select the appropriate carrier and send USSD codes ( some codes will be interactive and some direct) based on the USSD return ,the program need to update mysql table flag. This is a mobile recharge system where a topup SIM will be place inside a MODEM. And the java program can DIAL USSD code using the modem and AT command. - Sim modem to be set up and tested. - SEO optimisation - Unlimited number of accounts - And others…. 1 - Read SIM Card Numbers: Input a USSD code like #123# which will be sent to all to selected SIM Cards ports of the GSM gateways. The USSD reply message will be read and the SIM numbers exacted from the replied messages and displayed. All USSD codes will be provided. 2 - Load Airtime to SIM Cards: Input a USSD code and amount, which will be used to load each selected SIM in the GSM gateway and the results displayed. Several read & reply steps are required in the top up process (we will provide an example). 3 - Check SIM Card Balance: Use USSD code to query the SIM card balance of selected ports. This can be done periodically or on demand. We'll be glad to work with candidates who have prior experience with USSD codes and new ideas are welcome on how to make the project more efficient.