can I use dynamic library(shared object) in my iphone app?
As Bernardo Ramos states in a comment: "Since iOS8 we can use dynamic libraries".
Dynamic libraries are not allowed by the App Store. No code may be loaded at run-time. The answer is to convert them to static libraries and compile them into the application.
From iPhoneOSTechOverview:
"If you want to integrate code from a framework or dynamic library into your application, you should link that code statically into your application’s executable file when building your project."
Read "should" as "must"
See SO Answer: Can create dynamic library for iOS?