Bootstrap is the most popular CSS Framework for developing responsive and mobile-first websites.
Flutter is an open-source UI framework developed by Google that allows developers to create high-performance, cross-platform mobile applications with a single codebase.
Redux is a state management library for JavaScript apps that provides a predictable and centralized way to manage application state. It enables developers to write actions and reducers that update the state in response to user interactions, server responses, and other events, and can be used with a variety of front-end frameworks and back-end technologies.