I have developed very basic iphone app for CiviCRM using Titanium framework.
- Allows users to "Search Contacts" from their remote CiviCRM database.
- Add Individuals.
- App uses CiviCRM REST interface so you can scale it according to your needs.
You can get the code from our public svn repository: http://svn.civicrm.org/tools/branches/v3.2/other/iphone_1.0/
If you want to check this app, first you need to install Titanium framework and then import above code as New project.