An application that lets you see through the camera while working with cardboard.
An app that creates an ical feed out of your due date trello tasks that you can then integrate to Google Calendar or Outlook.
A small site that uses Pocket's (formerly "Read it later") API to create a basic "to read" list that links to the URL itself and not into pocket's rendering and thus skips a few mouse clicks.
An extension to mousetrap.js that auto-generates a help lightbox for your shortcuts.
A map of the Israeli "Red Color" alarm system that alerts against missiles.