For one of my company's web apps (that customers use), for internal development, if too many errors occur within 1 second, it shows a "You're in deep shit :O!"

For one of my company's web apps (that customers use), for internal development, if too many errors occur within 1 second, it shows a "You're in deep shit :O!" dialog and starts pulsing the page background red. It brings some humor to an absolutely terrible situation. But the build strips it for production during minification along with a bunch of other development-only code that will never make it in. Just be careful, and have fun. It's what hacking's all about. :)