This guide provides a comprehensive tutorial on implementing a user authentication flow in a React Native app using the latest versions of react-navigation and react-native-firebase, along with Firebase SDK as the backend service. It outlines the setup of a development environment, the creation of reusable components, and the configuration of navigational flows using react-navigation. The tutorial includes detailed steps for creating both login and signup screens, establishing a stack navigator for screen transitions, and integrating Firebase for email authentication. Additionally, it covers the use of an authentication provider to manage user states and actions like login, registration, and logout. The guide emphasizes the modular approach of react-native-firebase, allowing developers to install only the necessary modules for specific Firebase services, thereby streamlining the development process. The tutorial concludes by demonstrating how to verify user accounts in Firebase and includes a GitHub repository link for accessing the complete code used in the demo.