iBonsai is a unique digital abstraction of the bonsai experience.
I've had way to much fun with this app. Lately, when looking to release some stress, I sit and grow little iBonsai trees and listen to the ambient music.
Every tree grown is different, and in changing the settings you can grow some amazing to crazy looking trees. Another neat feature is that you can use your finger to turn and spin your tree to get a 3D view of it.
The app is $0.99, but well worth it.