useful opensource components & opensources apps

http://stackoverflow.com/questions/640805/open-source-ios-components-reusable-views-controllers-buttons-table-cells-e

http://www.cocoacontrols.com    #mainly for ui component

http://sstoolk.it           #mainly for well-structure liberaries

http://www.cocoacontrols.com/platforms/ios/controls

#######open source apps list##############

http://en.wikipedia.org/wiki/List_of_open_source_iOS_applications

http://maniacdev.com/2010/06/35-open-source-iphone-app-store-apps-updated-with-10-new-apps/

#######open source projects list ###############

http://www.iosdevcamp.org/2012/07/26/open-source-apps-at-iosdevcamp-2012/

http://www.cocoawithlove.com/2011/06/process-of-writing-ios-application.html

https://parse.com

####official sample code 

https://developer.apple.com/library/ios/navigation/#section=Resource%20Types&topic=Sample%20Code

https://github.com/xcatsan/iOS-Sample-Code

http://code.google.com/hosting/search?q=label%3aiphone

### 31sample code 

http://appsamuck.com/