iPhone SDKs and APIs

Hi Friends,
I'm going to list out some useful APIs/ SDKs for iOS Application Development environment. So, please make your closure look here.

1) Foursquare Real Time API
The foursquare APIv2 gives you access to all of the data used by the foursquare mobile applications, and, in some cases, even more.
Link : https://developer.foursquare.com/docs/realtime.html

2) Verizon Network APIs
Integrate into your mobile application Verizon's rich array of network functions.
LINK : http://developer.verizon.com/content/vdc/en/verizon-tools-apis/verizon_apis/network-api.html

3) Instagram API
Use these REST and Search APIs to utilize Instagram photos within your app.
Link  : http://instagram.com/developer/

4) Twitter :
 REST API, real-time search index, and streaming API to get tweets in real-time.
Link : https://dev.twitter.com/

5) Dropbox
Dropbox is a free service that lets you bring all your photos, docs, and videos anywhere, and share them easily.
Link : http://www.dropbox.com/developers/releases

6) Bump
Users "bump" their phones to share data within an app.
Link : http://bu.mp/api

7) iPhone ARKit
iPhone ARKit is an Objective-C augmented reality kit for iPhone.
Link : https://github.com/zac/iphonearkit/

8) Core AR
Core AR AR(Augmented reality) framework for iOS, based on a visual code like ARToolKit.
Link : https://github.com/sonsongithub/CoreAR

9) Viewdle Face Recognition
Viewdle's face recognition products to instantly tag friends & share your photos and videos as you create them, from your mobile phone, desktop, or browser!
Link : http://www.viewdle.com/products/ios/index.html

10) PDF Reader
Basic PDF Reader/Viewer for iOS.
Link : https://github.com/vfr/Reader

11) PSGoogleReader
Google Reader class for iOS (iPhone / iPad / iPod Touch).
Link : https://github.com/perspecdev/PSGoogleReader

12) Kal Calendar
A calendar component for the iPhone (the UI is designed to match MobileCal).

Link : https://github.com/klazuka/Kal

13) TouchRSS
TouchRSS is a general purpose RSS and Atom reading framework.
Link : https://github.com/TouchCode/TouchRSS

14) TouchJSON
TouchJSON is an Objective-C based parser and generator for JSON encoded data. TouchJSON compiles for Mac OS X and iOS devices (currently iPhone, iPad and iPod Touch).
Link : https://github.com/TouchCode/TouchJSON

15) ASIHTTPRequest
ASIHTTPRequest is an easy to use wrapper around the CFNetwork API that makes some of the more tedious aspects of communicating with web servers easier. It is written in Objective-C and works in both Mac OS X and iPhone applications.
Link : http://allseeing-i.com/ASIHTTPRequest/

16) Mobile App Tracking
Track all your mobile web and app-2-app installs with one SDK.
Link : https://platform.mobileapptracking.com/#!/advertiser

17) ZipWeather
ZipWeather allows you to look up weather conditions by ZIP Code.
Link : http://www.appsamuck.com/day15.html

18) PhoneGap
PhoneGap is an HTML5 app platform that allows you to author native applications with web technologies and get access to APIs and app stores.
Link : http://www.phonegap.com/docs

19) Route-Me
Route-Me is an open source map library that runs natively on iOS. It's designed to look and feel much like the inbuilt iOS map library, but it's entirely open, and works with any map source.
Link : https://github.com/route-me/route-me

20)MobClix
Mobclix manages everything for you – bringing the best ads to one platform, and handling all the details so you can stay focused on building great apps.
Link : http://www.mobclix.com/developer

If any one has query then place you it over here.

Thanks and Regards,
Nilesh Prajapati