Superhuman is an AI-powered email inbox that aims to optimize email productivity and efficiency. It utilizes AI to automatically sort and prioritize important emails based on behavioral patterns and user preferences. The tool also includes features such as reminders, which help users stay organized and accountable by holding them to their set deadlines. Additionally, Superhuman offers an open rate tracker, allowing users to see if and when their emails have been opened, and an undo send feature that lets users retract emails shortly after sending them. With its AI capabilities and productivity-focused features, Superhuman aims to streamline the email experience and help users manage their inbox more effectively.