Building a web based application

Description - This is an application for a QR code base payment system which operates through iOS and android apps. The apps will take the request from the users and deliver the request to centralise server and server will do the process and send back the status to the apps back. Do design - Main server and apps for iOS and Android platforms. Cording language - Phytone Requirements - 01. Must make the central server and apps according to the international standers 02. Must use the hight security options 03. for the additional features can be charged separately. 04. Bidding price must include the use interface designing as well. 05. Central system must includes the authorisation levels and system managing features. 06. Full project must be web based 07. All the project data must handover to the local engineers at the end of the project. Payments - 01. First 25% of Downpayment will be released at the beginning. 02. Second 25% will be released at the completion of the server and the apps. 03. Third 25% will be released when the full project complete and handover (including the GUI). 04. Last 15% will be released after the review of the local engineers. 05. 10% will be released after 6 months later of the pilot test of the platform. ( Subject to ask and clarify and any issue by emails or any method before bidding or after but before start the project, Can be changed for the additional features request by the employer after start the project only ) ( All the flow charts and working can be provided )