Vercel recently launched its first iOS app, v0, aiming for a high standard reminiscent of Apple's design ethos. The development process involved numerous iterations and experimentation with various tech stacks before settling on React Native with Expo. The goal was to create a seamless experience for users, enabling them to convert quick ideas into tangible outputs without switching contexts. The app is designed to enhance mobility in creative tasks, rather than replicate the full functionality of their website. A key feature of v0 is its chat interface, which was meticulously crafted with specific requirements. New messages animate smoothly, and the chat is structured to provide a responsive and engaging user experience. The team utilized several open-source libraries like LegendList and React Native Reanimated to build the chat functionality. Composability was a priority; each feature was developed as a standalone plugin, allowing for a flexible architecture that could evolve over time. The article details the technical implementation of the chat system, including how messages animate in and how the app manages state without unnecessary re-renders. For instance, when a user sends a message, a shared value triggers an animation that enhances the interaction. The hooks used in the app, such as useFirstMessageAnimation, demonstrate how the team leveraged React Native's capabilities to achieve a responsive interface. This level of detail highlights the creative and engineering challenges faced during development, as well as the solutions the team crafted to deliver a native-like experience on mobile.