From
Amazon's press release, here is a concise listing of the apps mentioned there:
Netflix
Rhapsody
Pandora
Twitter
Comics by comiXology
Facebook
The Weather Channel
Quickoffice Pro
games from Zynga, EA, Gameloft, PopCap and Rovio
Allrecipes
Bloomberg
Cut the Rope
Doodle Fit
Doodle Jump
Fruit Ninja
Jenga
LinkedIn
Zillow
Airport Mania
Battleheart
Pulse
The Cat in the Hat
Jamie's 20-Minute Meals
IMDb Movies & TV
Monkey Preschool Lunchbox
More apps will be released for Kindle Fire soon. The Amazon Appstore also has a free "paid" app every day, and once you've downloaded an app it's available on Kindle Fire as well as your other Android-based devices. Also,
here is a listing of free Android apps in the Amazon Appstore.