Hi Prakash,
If you are using the SAPUI5 mobile javaScript library and creating our app using the available components in the library. I think it is ok to call it a SAP Fiori application. SDK path https://sapui5.netweaver.ondemand.com/sdk/explored.html
But If you are using the BO Design Studio components to mimic the look and feel of a Fiorui App.
. I think you should call it a SAP Fiori like app.