Sudowrite is an AI-powered writing tool designed to aid writers in breaking through writer's block by suggesting improvements and alternatives to their written work. The tool's key features include a rewrite function that rephrases dull or repetitive sentences, a brainstorm function that generates different ways to express a thought, and an expand function that helps develop a short description or an idea into a more detailed explanation. The tool is aimed at helping writers enhance their creativity, improve their writing, and save time on editing.