For the different types of animation

http://www.cimgf.com/2012/01/11/handling-incoming-json-redux/

For the zip file and parsing the images from server

http://www.touch-code-magazine.com/update-dynamically-your-iphone-app-with-new-content/

For the gallery or grid view for the iPhone

https://github.com/gdavis/FGallery-iPhone

For the rotating an object by center by touch in iPhone

https://github.com/hollance/MHRotaryKnob
http://rdsquared.wordpress.com/

For the different kind of demo for iPhone

http://stackoverflow.com/questions/1939/how-to-articles-for-iphone-development-and-objective-c

For the Encryption and decryption of the url

http://blog.objectgraph.com/index.php/2010/04/20/encrypting-decrypting-base64-encode-decode-in-iphone-objective-c/

For the barcode url parsing

http://searchupc.com/developers/login.aspx