Can you explain what Flutter is and what it is used for?

Flutter is an open-source framework from Google for building cross-platform mobile, web, and desktop applications with a single codebase in Dart.

The main purpose of Flutter is to quickly and efficiently create beautiful interfaces with high performance, close to native, thanks to its own rendering engine.

An example of using Flutter is developing an application that works equally well on Android and iOS without the need to write separate code for each platform.