I read this article, changed my method, and was amazed when a week later my 18 mo. old knew his colors backward and forward. Even if youre not trying to teach colors, read this article from Scientific American, its fascinating!
10 apps for preschoolers: 1. Montessori Crosswords 2. Handwriting without Tears: Wet, Dry, Try Capital Letters and Numbers 3. TeachMe Toddler 4. Monkey Preschool Lunchbox 5. Park Math – Duck Duck Moose 6. Bugs and Bubbles 7. PBS Kids Video 8. Farm 123 Free – StoryToys Junior 9. Little Writer – The Tracing App for Kids 10. Rover – The Browser for Education