Sonar is a platform for debugging mobile apps on iOS and Android. Visualize, inspect, and control your apps from a simple desktop interface. Use Sonar as is or extend it using the plugin API.
Radare is a portable reversing framework that can...
Disassemble (and assemble for) many different architectures
Debug with local native and remote debuggers (gdb, rap, webui, r2pipe, winedbg, windbg)
Run on Linux, *BSD, Windows, OSX, Android, iOS, Solaris and Haiku
Perform forensics on filesystems and data carving
Be scripted in Python, Javascript, Go and more
Support collaborative analysis using the embedded webserver
Visualize data structures of several file types
Patch programs to uncover new features or fix vulnerabilities
Use powerful analysis capabilities to speed up reversing
Aid in software exploitationzines about systems & debugging tools
A runtime developer console, interactive debugger and REPL for PHP. PsySH can be used as an interactive debugger, much like JavaScript's debugger statement, saving you from endless var_dump() and die() iterations.
Free PCRE-based regular expression debugger with real time explanation, error detection and highlighting.
Webhook Tester allows you to easily test webhooks and other types of HTTP requests.
Differentiate HTTP headers and content body of two GET URLs.
Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.
A tool for one person pairing.
RequestBin gives you a URL that will collect requests made to it and let you inspect them in a human-friendly way.
Use RequestBin to see what your HTTP client is sending or to inspect and debug webhook requests.
Kint for PHP is a tool designed to present your debugging data in the absolutely best way possible.
In other words, it’s var_dump() and debug_backtrace() on steroids. Easy to use, but powerful and customizable. An essential addition to your development toolbox.
Charles is an HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP and SSL / HTTPS traffic between their machine and the Internet. This includes requests, responses and the HTTP headers (which contain the cookies and caching information).
A sexy server logger console in Firebug
A tool for quickly profiling variables and resources used by PHP.
FirePHP enables you to log to your Firebug Console using a simple PHP method call.
All data is sent via response headers and will not interfere with the content on your page.
FirePHP is ideally suited for AJAX development where clean JSON and XML responses are required.
A JavaScript file you can insert into your pages to simulate the Firebug console in browsers that are not named Firefox.