When the user pushes the ? key, QuestionMark.js triggers a modal window that displays keyboard shortcuts for your app — similar to what happens on Twitter, Gmail, GitHub, etc. The modal is removed when the ESC key is pushed or the user clicks behind the modal.
I think every app that has keyboard shortcuts should do this. This could also be a generic ‘help’ menu for the app, but that would require some tweaking to the code and the CSS. For now, this works primarily as a shortcut keys menu.
