It's not a secret that tablet computers are great learning tools for kids with ASD. It's been reported on many times. There are even really boring scholarly articles written about it.
I want to give a shout out to some of the best learning apps I've come across. Max and Dexter both love these apps. You should check them out for your kids wether they are on the spectrum or not. Really good stuff here.
Endless Alphabet: I can't say enough about how great this app is. It teaches letters and vocabulary. It is beautifully designed and animated. And it has TONS of personality and fun. Endless Alphabet, Endless Reader, Endless Numbers, Endless Word Play. Get them all. Seriously.
Loopimal: This one teaches cause and effect relationships. And it's crazy fun. I'll even play with it sometimes. It's kind of brilliant.
Sago Mini Space Explorer: There are a whole bunch great of apps made by Sago Mini but my kids' favorite is the Space Explorer. They can be a bit pricey but if you watch you can find them on sale or in discount bundles. A lot of people would say that these apps are "just for fun" and aren't really "educational." But those people are dumb and don't understand just how important fun is in the life of a child.
These apps are great for any young child really. Check them out.