An iOS app which was basically a wrapper for a giant jQuery eForm.
~5000 lines of custom JS and it broke ALL THE DAMN TIME. A team of us worked on it for about a year and all we ever did was fix bugs. But the bug count never went down. The bugs just got replaced with more bugs.
Thankfully its not live anymore.
After the global thermonuclear war, all that will remain is cockroaches and jQuery.