FLEX is an in-app debugging and exploration tool for iOS development.
FLEX addresses the challenge of inspecting and modifying application state during development by embedding a toolbar directly within your running app. The tool operates entirely inside the application process, eliminating the need for external debuggers or remote servers. When activated, it presents a floating interface that grants access to the view hierarchy, object properties and instance variables, network request history with timing and response data, the file system sandbox, database contents, system logs, and the complete heap of allocated objects. You can dynamically modify properties and call methods on live objects, browse all classes in your app and system frameworks, and access commonly needed objects like the app delegate and root view controller.
FLEX suits developers who want immediate, hands-on inspection of their app's runtime state without leaving the application itself. It works in both the simulator and on physical devices, with keyboard shortcuts available in the simulator for quick activation. The tool is particularly valuable during development and testing phases when you need to understand or modify application behavior on the fly. Unlike remote debugging approaches, FLEX requires no connection to Xcode or a separate debugging server, making it accessible in any environment where the app runs. The project does not support tvOS natively, though community forks exist for that platform.
The project maintains active development with regular updates and improvements to its debugging capabilities. The codebase shows consistent refinement of existing features rather than major architectural shifts. Community engagement appears steady, with the project accepting contributions and maintaining compatibility with current iOS development practices. The tool has established itself as a stable, well-documented resource within the iOS development community.
