This framework allows developers to build native mobile apps for iOS and Android using a single shared JavaScript or TypeScript codebase. It is built on top of the Expo CLI tool, which provides an easy-to-use interface for creating React Native projects. End-to-end testing is a technique used to test the entire application flow, simulating real user scenarios. Detox is a gray box E2E testing automation framework that tests mobile apps on real devices or simulators/emulators, interacting with them like a real user. It supports React Native projects as well as pure native ones and has features such as cross-platform testing, running on devices, avoiding flakiness, executing tests on CI platforms, and using Jest or Mocha test runners. To use Detox, developers need to set up their environment with macOS 10.15 or higher, XCode 11 or higher, Node.js, NPM, Watchman, Homebrew, React Native CLI or Expo CLI, CocoaPods, Java JDK +8, and Android Studio, Android SDK, and Virtual Device. The Detox configuration file can be customized to match the app's build variants, binary path, devices, and other configurations. Changes for Android apps require adding native Detox dependencies, installing Android Espresso, and configuring network-security exemptions. E2E tests need to be modified to match the app's steps. To integrate Detox with Bitrise, developers can create a free account, set up their repository access, configure build configuration, add integration Steps, and run Detox Build and Test scripts. The final step is sending a Slack message with the build status.