Google APIs Client Library for Objective-C
Project site https://github.com/google/google-api-objectivec-client
Discussion group http://groups.google.com/group/google-api-objectivec-client
This library has been replaced by Google APIs Client Library for Objective-C For REST. New applications should use that instead; existing application should be updated as soon as possible as the Google servers will eventually stop accepting JSON-RPC requests.
Written by Google, this library is a flexible and efficient Objective-C framework for accessing JSON APIs.
This is the recommended library for accessing JSON-based Google APIs for iOS and Mac OS X applications. The library is compatible with applications built for iOS 3 and later, and Mac OS X 10.5 and later.
The library may also be used without generated interfaces with JSON REST and JSON-RPC APIs.
If you have a problem or want a new feature to be included in the library, please join the discussion group. Be sure to include http logs for requests and responses when posting questions. Bugs may also be submitted on the issues list.
Google Data APIs: The library for older, XML-based APIs is still available.
Other useful classes for Mac and iOS developers are available in the Google Toolbox for Mac.