KnowItAll is an AI chatbot app powered by OpenAI's ChatGPT-4, offering various features like writing essays, generating social media posts, fixing typos, and more. It serves as a personal assistant for tasks such as coding, summarizing articles, translating texts, and creating video scripts. The app is free with optional in-app purchases and does not require login or email for use. It's designed to save users time and effort across a range of writing and productivity tasks.