Open Source 2D Game Engine for iOS

The Sparrow Framework

The Open Source Game Engine for iOS

http://gamua.com/sparrow/

cocos2d for iPhone

cocos2d for iPhone is licensed under the MIT license.

http://www.cocos2d-iphone.org/

Particle Effects editor 

(爆破效果編輯器)
http://particledesigner.71squared.com/