Prompt Selected is a browser extension that allows users to run their custom ChatGPT prompts on any selected text. Key features include unlimited custom prompts, prebuilt prompt examples, support for the latest GPT model, prompt history, and no data tracking. It's incredibly versatile, covering use cases such as grammar corrections, article summarization, language translation, simplified explanations, and social media post creation. The tool is free to use and requires users to bring their own API key.