Rest2mobile is a project providing an Xcode and IntelliJ UDEA plugin along with a command line tool from Magnet submitted by Pascal Jaillon that allows you to automatically generate native objective-c code for communication with a a REST service.

The plugin provides a nice interface allowing you to retrieve the JSON payload from the REST service and generate the code with a couple of clicks. The code works with the rest2mobile SDK for communication which uses AFNetworking to communicate with the REST API.

You can find the rest2mobile plugin and command line tool over on the rest2mobile homepage.