Free is good! Here are the fun free apps that I found today. There is a pretty good list today. Remember that most of these are free for a limited time.
Kingdoms at War ~ online war game
Optical Illusions ~ ask the question why things we perceive visually sometimes differ from objective reality.
Composure: Zen Garden ~ calming garden that you can groom and design to your liking.
PirateTweets - Arrr ~ Automatically filters all your friends tweets into Pirate slang as well as tweets you submit