We have an Apple iPad and we are incorporating it into our home-preschooling one game at a time. Two games I have found to be great is iWriteWords and Little SkyWriters We bought the Handwriting edition of iWriteWords ($2.99) and the iPad app Sky ($1.99) and I love them because it fills a gap in what I've been teaching him at home
Elijah has this great wipe-clean book called Learn to Write your Letters ABC (it's in the Amazon list to the right) and we write the alphabet upper- and lower-case everyday. However, I'm afraid of over-correcting, creating frustration, and taking his enthusiasm for it down to nil. With both of these apps, he must follow the letter correctly, lifting his finger where he should and finishing the letter correctly. And they're still fun.
These apps were good for my Elijah with the speech delay because I was able to have him repeat words that the man in Sky Writers said or the words the lady said in iWriteWords. He also must tell me which one he wants by saying "I want -" to first get the app, and again for the features in the game. And if he does a good job, I encourage him to say "yay!" and pretty soon, he's engaging in spontaneous speech.
There's another review with a video for Little Sky Writers here by Best iPad Hacks. The iPhone Mom wrote a great review of iWriteWords here and if you search for it on youtube, you can watch kids play it. Both are well worth it in alphabet toddler game world.
Amanda & Cubs