Have to write about this because I like it so much :) This app simply changes your homescreen wallpaper to a beautiful pond with swimming kois. It changes your screen to soft water surface and you can interact with it by creating ripples with your finger.
I don't need to say more, Install it and experience it yourself!
Not recommended for slower Android devices though because it eats up resources and also battery life. I used to be very concern about saving my battery life, but after using this live wallpaper I just couldn't give it away.. now I don't care about battery life anymore as long as I have this.
The paid version simply add customizable fish sizes, background image (different ponds) and raindrop effect. Free version is good enough but if you want to support the developers, it's only 99 cents.