Cross Platform Application

Hello,\r\n\r\nI want to develop an application that works with our existing database of customers, suppliers and inventory\r\n\r\nRequirements:\r\n\r\n1. Cross Platform: Run on Windows, Android, IOS, Chrome OS\r\nUse code that minimizes changes on each platform.\r\n\r\n2. Client Application with own local database to run without any connection to internet / server\r\nWhen connection to internet and server connection available, send and receive changes with no user intervention.\r\n\r\n3. Access local resources of the client operating system \r\n- examples include COM, LPT, USB, Bluetooth, Network, File System, Client OS API\r\n\r\n4. Program based on a established framework system with ample community support & tools available\r\n\r\nI have more detailed specifications but this should be enough to give you a good idea of what is needed\r\n\r\nThis project is hourly 20 to 40 hours per week and long term of 6 months or more.\r\n\r\nNeed to have a set work schedule of specific days and hours working\r\n\r\nIn your response, please tell me how you will meet each requirement - 1 to 4 above. \r\n\r\nThe more detail provided on how you will accomplish the better.\r\n\r\n\r\n\r\n