FLEX vs OpenOCD

FLEX is a free, open-source debugging and exploration library for iOS applications. It runs inside the app and places a toolbar in a window above it, allowing developers to inspect and change application state without an LLDB or Xcode connection or a remote debugging server. The tool can inspect view hierarchies, find live heap objects, show and modify properties and ivars, and call methods. Its network history covers NSURLConnection and NSURLSession requests with timing, headers, and responses. Developers can browse app bundles and sandboxes, inspect SQLite and Realm databases, and view or edit NSUserDefaults values, including strings, numbers, arrays, and dictionaries. FLEX works in the iOS Simulator and on physical devices, supports Objective-C and Swift, and requires an iOS 9-or-later target. Installation options include CocoaPods, Carthage, Buck, manual Xcode integration, and Swift Package Manager.

OpenOCD provides debugging, in-system programming, and boundary-scan testing for embedded target devices through a debug adapter. It communicates with targets over JTAG or Serial Wire Debug (SWD), and can run as a server for GDB clients. Users can also interact through Telnet or GDB; its Tcl interface is intended for machine interaction, and configuration files can contain commands using the documented Tcl scripting API. The target list includes ARM, MIPS, RISC-V, Xtensa, ARC, AVR32, and other architectures. Release 0.12.0 notes support for Espressif ESP32, ESP32-S2, ESP32-S3 cores, and Raspberry Pi Pico RP2040, along with Zephyr and a no-RTOS option. OpenOCD supports remote debugging and exception breakpoints. It is free and listed for Linux, macOS, Windows, and self-hosted setups. The project says it is packaged in popular operating-system repositories and provides access to source code; community binaries are marked unofficial. Host configuration may take extra steps: Linux usually needs a udev rule for adapter access, and Windows requires driver configuration for each peripheral.