I borrowed this listing from this blog: http://aplacecalledkindergarten.blogspot.com/2010/08/i-love-my-new-ipad.html
Robot Reader (free) a robot voice tells you the letter, sound, word and definition of something that starts with that letter
1 2 3 Color ($1.99) I love this app! It is basically a fancy color by number, letter or color picture. The letter, number or color only disappears if you choose the right one.
Letters A to Z ($.99) This is the app that I am going to use first. It is letter and sound flash cards with cute illustrations.
iWrite Words ($2.99) Great app for practicing writing upper and lowercase letters, numbers and words. Love how you have to send the letters down a "hole" when you are finished.
Letter Lab ($2.99) Great app for writing upper and lowercase letters.
Pocket Charts! Beginning Sounds ($1.99) Match a letter to a picture of something that starts with that letter. The only thing I do not like about this app is that the pictures are shown in alphabetical order.