Autoresponder.ai is a chatbot tool that allows users to send automatic replies on popular messaging platforms such as WhatsApp, Facebook Messenger, Instagram, Telegram, Signal, and Viber. It offers features such as unlimited messaging, custom rules for different messages, and API/webhook connections. Users can also integrate it with GPT/GPT-4 and Dialogflow AI to trigger custom actions. The tool claims to reduce workload and provide instant replies while being highly customizable.