Microdot is a simple self destructing web chatroom created in 9 hours (and updated later on to finish it).
According to Wikipedia, "A microdot is text or an image substantially reduced in size onto a small disc to prevent detection by unintended recipients". Microdot in this case is a chat app designed to allow for secure, self-destructing communication for anyone who doesn't want their text to be read by unintended parcicipants.
The chat function is based on websockets (using the node.js library socket.io).
A live version can be found at http://microdot.tech/