If some of you may have updated to the latest version on WordPress, i.e v3.9, you will notice that the “Lightning Icon” is not showing anymore. This is due to the fact that WordPress has updated the TinyMCE plugin they use to power the panel where you write your Posts and Pages.
We’re working on a fix and will update this post as and when it’s ready.
In the meantime you can make do with the “ShowDown Help” panel that is shown when you create a new Post/Page to know how you can enter your ShowDown shortcodes.
We thank you for your patience.