The Electric Company on PBSkids is hosting a game called Mine Cart Mash (developed by sesameworkshop) to teach kids how to identify that words can be changed by adding a single letter. Each letter added to a word changes a single letter sound to the sound of a a digraph. The sound of the letter “s” becomes the combined sound of “sh” together.
Disclaimer: This can be challenging for students with dyslexia, as it is more difficult for them to decode at the rapid speed that this game is set at.