The Esper Device Provisioner Tool V4 has been released, offering a more robust and user-friendly experience for companies creating custom-built Android devices. The tool was rewritten in TypeScript to improve security, performance, and maintainability. It now features dark mode support, reduced app size, and improved startup time. Additionally, it includes Linux support, improved aesthetics, and enhanced error handling. The update also enables users to select templates and applications more easily, providing a cleaner and more intuitive experience.