Druid-Quest is a project mainly written in OBJECTIVE-C and C, it's free.
Druid Quest
A puzzle game for the iPhone.
Warning: This was my first experiment with Cocos2D (I only used C++ for gamedev before) and the code sucks. Take a look at my other games if you want some non-sucking code :)
License GPL3 (c) Leon Szpilewski, 2009-2011