POS System Developer for our Clients

We are planning to make a POS Management System that manage sales , purchases , services , qoutations , reports , profit , discounts , debits , installments , expenses , users , roles , multi-branch , multi-store , multi-inventories , multi-language , multi-currency , multi-sale-prices , FIFO method , Avg cost method , general reports on each section and detailed reports using filter from a date to a date with specific filter values and summery , point of sale page , support markets , restaurants , print barcode , import & export excel , license generator for activating client apps


We want to resell te POS System as a fully developed end-user app and can be installed fully and easily by the client and setup easy 1 click install

client can link more than 1 copy on the same network
client can activate his license using internet


So we need a full solution that could work on
Windows , Android , IOS
same funtionalities on all platforms