Nstive (swift / java) Reasons: You can do customizations easily (In big complex app you simply can not go for cross platform due to lack of customization) Plenty of resources are available for [Android Tutorials] (https://demonuts.com/) and iOS tutorials. You can build UI Layouts and programming classes with full control in developer's hand. Complex app will have future expansion , this is where customization and native scripts will actual play it's role.