React Native is a framework for building native mobile apps for iOS and Android in one shared JavaScript or TypeScript codebase. To install and build the first app, Expo CLI is recommended for new developers, while React Native CLI is preferred for those with existing mobile development knowledge. A Mobile Devops platform called Bitrise supports various features like managing dependencies, signing codes, deploying to testers, and releasing apps to stores. The article assumes a Jenkins server installed on a macOS machine and guides the reader through migrating their iOS app from Jenkins and fastlane to Bitrise, covering steps such as configuring environment variables, adding integration steps, and setting up workflows for Android and iOS apps. With Bitrise's features like parallel builds and Gen2 build infrastructure, the migration process can significantly reduce build times and make CI/CD easier.