Using local server with self-signed certificate

I want to use local server with self-signed certificate. But i have some questions? What should i enter for “common name” (hostname) when i create certificate.Because I dont have any domain name. And i want to use server with public and private ip address together. Is it possible? If i use self-signed certificate, how android and ios application will work. Because i know that android and ios wont allow self-signed certificates until adding certificates manually or pinned to application.