Nothing here yet really.

Image size is based on back.png(supports .gif, .png and .jpg, no changing anything either, must stay named back.* though)
Easy to use smiley system, drag and drop the smilies you want into into the folder then to use just put in a signing the filename(not including the .*extension*)
AdminCP!(password on line 3 of admincp.php)
Updates every 2 seconds if changed.

.htaccess makes index.php into sig.png so link to that if your server supports .htaccess. If not you must do the folder method.