I didn't see another thread for this. Koi Pond
been the Top Paid App ($0.99) in the store for a while now and I wanted to see who else has had fun with this! It's a simulated koi pond with about 5 different patterned koi fish. You can choose one of four pool floors, amount of lily pads, amount of fish (0 up to ~6), and a mixture of background nature sounds. When you run your finger across the water (screen), ripples spread from your fingertip. Koi swim away and return after a few moments. You can shake the iphone to add some fish food which the koi eat.
It's quite relaxing and well done. The koi wander in and out of the screen, the iphone screen edges act like boundaries for the surface ripples so they bounce quite realistically. The authors (Blimp Pilots) haven't put in interacting shadows but I imagine that it would be a pain to implement 3-d fish. It also doesn't seem to support multi-touch. But they've already updated their program once since release so I expect they'll keep making changes!
Anyone else bought it?