We've only been doing this about a month. My dd2 is 12 months.
I started with printed doman style cards, but she got bored so quickly, I changed over to Keynote (like PowerPoint) presentations.
Today she started to say "crab" a millisecond before the presentation did. It may have been memorization of the order. But that's impressive!
Anyhow, this is fun, I just had to share.