TraceKit : Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.
Firebug Lite : A JavaScript file you can insert into your pages to simulate the Firebug console in browsers that are not named Firefox.
polyfill : polyfill makes web development less frustrating by selectively polyfilling just what the browser needs. Use it on your own site, or as a service.
Sonar : 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...
Autotrack : Automatic and enhanced Google Analytics tracking for common user interactions on the web.