Flutter is Google’s UI toolkit for building beautiful, natively compiled applications for mobile, web, and desktop from a
single codebase - (official Flutter website).
Google Flutter is a groundbreaking new technology that streamlines the process of developing cross-platform mobile applications. Originally developed by Google and released under the new BSD license, Flutter is an open-source toolkit for building applications for mobile, web, and desktop platforms from a single code base. This eliminates the need to construct an iOS and Android app separately, thus speeding the mobile app development process and reducing costs.