SimUtil is a Dart-based terminal UI/CLI for managing iOS simulators and Xcode Derived Data. It wraps `xcrun simctl` to list, boot, shut down, install, launch, and interact with simulator devices, and adds conveniences like showing/cleaning Derived Data. The app is operated entirely from the terminal and stores user preferences in `~/.simutil/settings.yaml`, including a `plugins:` section for custom commands. Architecturally it separates terminal UI components (`lib/components`) from services (`lib/services`) such as `CommandExec` (a shell-command abstraction), `UserConfig` (YAML settings with first-run defaults and scalar merge), and Derived Data helpers. A `tool/generate_changelog.dart` code generator parses `CHANGELOG.md` and emits typed Dart data so the app can show post-update changelog dialogs. Tests cover the changelog generator and config file behavior, and CI runs build/install verification across platforms.
InjectionIII is a macOS menu bar application that enables hot reloading of Swift, Objective-C, and C++ code in iOS simulators and devices. It works by watching for source file changes, recompiling them using Xcode build logs, and dynamically loading the resulting dylib into the running app using techniques like interposing, vtable patching, and Objective-C swizzling. The app consists of a daemon with a file watcher and injection server, while the client-side code (bundled as injection bundles or via the HotReloading Swift package) handles compilation and injection. It supports standalone injection without the app running, injection on real devices, and integration with SwiftUI. The codebase is mature and actively maintained, though it contains legacy C/ObjC components and is tightly coupled to Xcode build log parsing.