This Sparrow extension adds support for WebP in Sparrow. You can change all PNG and JPG files to WebP to reduce the size of your game.
Download WebP tools (cwebp) from: https://developers.google.com/speed/webp/download
Create and include WebP.framework in your proyect. Please consider to read http://www.ioncannon.net/programming/1483/using-webp-to-reduce-native-ios-app-size/