DeviceKit is a Swift library that provides a value-type replacement for Apple's UIDevice class, enabling device detection across iOS, tvOS, and watchOS platforms. It identifies real devices and simulators (iPhone, iPad, iPod, Apple TV, Apple Watch) and exposes properties such as screen diagonal, aspect ratio, PPI, battery state, CPU, camera types, and hardware features (e.g., eSIM, 5G, USB-C, LiDAR, Apple Pencil support). The library uses a code generation pipeline: a Python template engine (GYB) processes a template file (Device.swift.gyb) to produce the main Swift source (Device.generated.swift), which is checked into the repository. The architecture is a single Swift framework with conditional compilation for each target OS, and it depends only on Apple's UIKit/WatchKit. The project is actively maintained with frequent releases aligned with Apple device launches, comprehensive tests, and CI across multiple simulator targets.