Compose AI is a free Chrome extension that uses AI-powered autocompletion and text generation to help users save time and automate their writing. It can be used to generate ideas for stories, blog posts, research topics, and more. The tool can also autocomplete sentences and suggest new ways to say things. It seamlessly integrates with existing platforms and can be used to compose emails and generate professional replies. Compose AI is personalized to the user's voice and writing style and learns over time. The plugin is free to use forever, and there is a premium version with some advanced features.