Google APIs Client Library for Objective-C for REST
Project site https://github.com/google/google-api-objectivec-client-for-rest
Discussion group http://groups.google.com/group/google-api-objectivec-client
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, macOS, tvOS, and watchOS applications.
To get started with Google APIs and the Objective-C client library, please read USING.md for detailed information. The example applications can also help answer some questions, but there isn't an example for every service as there are just to many services.
Generated interfaces for Google APIs are in the GeneratedServices folder.
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 much older library for XML-based APIs is still available.
Other useful classes for Mac and iOS developers are available in the Google Toolbox for Mac.