Expo.dev is a framework and platform for building native iOS and Android applications using JavaScript and React. It significantly simplifies the development process by abstracting away much of the complexity associated with native mobile development, allowing developers to focus on building features rather than wrestling with build tools, device provisioning, and native code.

By providing a curated set of pre-built components and APIs, Expo enables developers to create powerful and feature-rich applications quickly. This includes access to device functionalities like camera, location, push notifications, and more, all through a unified JavaScript interface. The platform also offers powerful tools for sharing, testing, and deploying your applications, making the entire lifecycle from development to production more streamlined.

Expo's approach democratizes mobile development, making it more accessible to web developers who are already familiar with JavaScript. It allows for rapid prototyping, testing on real devices without the need for native build environments, and a faster time-to-market for your mobile app ideas. Whether you're building a simple utility or a complex application, Expo provides the tools and infrastructure to make it happen efficiently.