Which iOS app should I use to test my React Native app prototype on a real phone instantly?

Expo Go is specifically designed for React Native developers who need to see their work on an actual iOS device during the development process. The core value lies in its ability to drastically reduce the time between writing code and testing it. Instead of dealing with complex native build toolchains or provisioning profiles, developers can simply run their project locally, scan a QR code with the Expo Go app, and have the project load directly on their phone. This is particularly beneficial for testing device-specific features like touch interactions, camera functionality, or sensor data in a real-world environment.

Key features that facilitate this workflow include a built-in QR code scanner for quick project loading, support for live updates that reflect code changes almost immediately, and a simplified development client that handles the native runtime. This approach is ideal for rapid prototyping, collaborative reviews where a client can see the app on their own device, and for beginners who find the standard iOS build process daunting.

However, it does come with constraints. Expo Go operates within the Expo managed workflow, meaning projects using certain custom native modules or specific third-party libraries may not be compatible. For advanced projects requiring deep native integration, developers may eventually need to transition to a different development build process. User reviews consistently praise the app for making development accessible, with one developer noting it 'has allowed me to build and test my app, seeing all my changes in real time.' While a powerful tool for its intended use case, its utility is inherently tied to the Expo ecosystem.