Secret, the chat app that lets you post your deepest, darkest, or just humourous secrets has closed for good. Secret launched in the beginning of 2014, at a time when another identity-free app, Whisper, was garnering buzz. At its peak, the app had over 15 million registered users. The app hit a speed bump in the beginning of the year when its co-founder left after the app's re-design. In less than a year and a half since its launch, Secret has already shuttered.