Hi Parth,
A. When you are creating a custom Fiori client using SMP SDK the plugins will be present in the app by default. You can check the list is plugins using the command cordova plugins.
Fiori client is a cordova project so you are free to add any cordova plugins to the project. You can download the SMP SDK for free from https://store.sap.com/sap/cp/ui/resources/store/html/SolutionDetails.html?pid=0000013098&catID=&pcntry=US&sap-language=E…
You can follow these guides on how to use these plugins with the cordova app : Getting Started with Kapsel - Part 1
B. SMP server is not required if you are using plugins which are not associated with SMP 3. Ex. Barcode Scanner, Encrypted Storage.
A non customizable verion of Fiori client is available in Apple Store and Google play, this is recommended only for evaluation purpose, not for production.
How to create custom Fiori client: SAP Custom Fiori Client - YouTube
Getting Started with Kapsel - Part 14 -- SAP Fiori Client (New in SP04)
Regards, Midhun
SAP Customer Experience Group - CEG