Does Qt Creator make APP in Native Code for iOS and Android? Why?
the compiled code depends on the compiler used. As Qt is a c++ framework the compiler used for android for example is the Google ndk-compiler producing architecture dependent native code. For ios, the clang compiler allows mixing c++ and objectiv-c code, but usually a qt project on ios is c++ only.
Technically Qt Creator is only an IDE so it doesn't produce anything by itself. Back to your question, what do you mean by "Native Code" ? Qt for Android builds your application as a c++ library that will be loaded at runtime through the JVM but it still is C++.
As for iOS, it's again C++ or if you need some native stuff, then you usually end up with Objective-C++ code. Both will be built by Clang.