Isn't it possible to have an ovi address by, for example, being a customer? a happy customer, in this case?
Yes it is, anybody can sign up for a free ovi.com email account. Nokia employees generally have a @nokia.com email address.
You cannot however create an app that is truely native..
What is "truely" native? What are the other kinds of native code? NDK allows you to build native applications that execute directly on the processor, as opposed to inside Dalvik, that's native in my books. Moreover, if you make your UI in OpenGL you don't even have to use Android UI elements.
His email address is
Either that or he just happens to have signed up for a free ovi.com email account.
You have mail.