We have studied and analyzed the flow of multiple end-applications in mobile phone OS (like Android/iOS). Some cross-platform applications – mobile phone, desktop, and web application uses the same database, in that case, they all use the centralized database, for example, WhatsApp, Facebook, Instagram & others as well. We found that all the end application uses web-service or API to connect/communicate with the centralized database. Web-service or API helps end-applications to connect/communicate with the centralized database by working as intermediator. This WS/API can be developed using programming/scripting languages like PHP, JSP, .NET technologies, python, GO, ruby, PERL, and others.
Key words: PHP, JSP, .NET, python, GO, ruby and PERL.