xcode is free and available on iTunes store, but you need a mac machine and a developer account that may also be a free university account too for students. and if you don't have mac. then use Vmware and install virtual machine with mac iso vmware image.
there are some other ways too like flex which are being used for iPhone but xcode, which uses objective c is the formal by apple and is secure.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…