The Co-Keeper system was built using a shared code base fully written in Swift, ensuring high performance and seamless integration across iOS devices. The user interface was developed with SwiftUI, leveraging its declarative syntax to create a responsive and intuitive user experience. For the backend, Firebase was implemented to provide a server-less architecture that supports real-time data synchronization and updates, ensuring all users have access to the latest information instantly. This combination of Swift, SwiftUI, and Firebase enabled the development of a robust, scalable, and efficient property management solution.