Implementing modern authentication in an Ionic 2 app is simplified by using Auth0, which supports various social identity providers and features like multifactor authentication and single sign-on. This tutorial demonstrates how to utilize Auth0 and the angular2-jwt library to manage authentication, handle JSON Web Tokens (JWT), and efficiently implement login and logout functionalities. It covers setting up an authentication service to manage user sessions, using Auth0Lock for login, and integrating JWTs for secure API requests. Additionally, the process of enabling multi-factor authentication and refreshing tokens is explained, ensuring a seamless user experience by scheduling token refreshes and handling app startup scenarios. Auth0's integration with Angular and Ionic, along with its ability to simplify authentication complexities, allows developers to focus more on the application's core logic rather than intricate authentication details.