In the mobile app development cycle, various builds play distinct roles, each characterized by different stability and usability levels. Alpha builds represent the initial phase where core functions are present but may be too buggy for general use, often tested internally or by select external testers. Once feature-complete and stable, apps transition to the beta phase, where beta builds are tested by a broader audience in real-world scenarios to gather feedback and fix remaining issues. Nightly builds, produced automatically each day, incorporate daily changes and are typically unstable, serving as a tool for continuous integration throughout the development process. Finally, production builds are the stable iterations of the app, marked as "release candidates" after rigorous testing, and are distributed to end-users as the finalized product. Various build tools like GNU make, XCodeBuild, Ant, Maven, and Gradle facilitate the creation and management of these builds, with continuous integration practices ensuring that changes are promptly tested to maintain build integrity.