There's now an Amazon Echo app for American Girl! On it, you can explore the worlds of Julie and Melody, and there will be more characters added every month. You can download it onto your Echo and launch it by saying, "Alexa, open American Girl."
This seems cool, but I don't really like playing games on my Alexa, I just use mine for practical stuff. I do like playing some of the AG games on the computer and phone, though! What's your favorite? I used to love the McKenna app, but it stopped working.