Here are a list of games that Ethan has liked in the past or currently likes to play.
http://www.toddlerteasers.com/
http://appshopper.com/education/teachme-toddler
All of the i Write Words games, there are abc, ABC, numbers and words
http://www.iphone4kids.net/2009/06/20/iwritewords-learn-handwritting-by-playing/
Build a Word
http://itunes.apple.com/us/app/build-a-word/id329397984?mt=8