I work with an iMac running on MAC OS 10.6.8 and the version 2.57 of Blender.
I perfectly installed the script but I can't enable it...
On the console window, I have the following message :
Traceback (most recent call last):
File "/Applications/Blender/blender.app/Contents/MacOS/2.57/scripts/modules/addon_utils.py", line 207, in enable
mod = import(module_name)
File "/Applications/Blender/blender.app/Contents/MacOS/2.57/scripts/addons/io_export_objective_c_header.py", line 26, in
ImportError: No module named bpy_extras
Thank you very much
Update to a newer version of Blender. The current version is 2.63a. There was a change to the API around 2.59 IIRC that changed the namespace of bpy_extras.