MoPub is a mobile advertising platform that helps app developers and publishers monetize their applications. It provides tools for managing ad inventory, optimizing ad performance, and connecting with various demand sources to maximize revenue. The platform supports multiple ad formats, including banners, interstitials, and native ads, allowing developers to choose the best options for their apps. MoPub also offers analytics and reporting features, enabling users to track ad performance and make data-driven decisions to improve their advertising strategies.