The tutorial provides a detailed guide on securely storing user credentials in a React Native app using the react-native-keychain library. It emphasizes the importance of not saving critical information like login tokens or passwords in unsecured environments such as AsyncStorage. Instead, it demonstrates how to use react-native-keychain to save, retrieve, and delete credentials through methods such as setGenericPassword, getGenericPassword, and resetGenericPassword. The tutorial includes a practical example by building a basic login app with a dark-themed UI, showing how to securely store tokens and authenticate users, and also covers creating a welcome screen that displays the user's name post-login. Additionally, it integrates useEffect to retrieve stored credentials upon app re-entry, ensuring a seamless user experience. The guide concludes by encouraging developers to implement their complete login systems using these practices while maintaining user security.