I´m getting this error in XCode:
2013-08-23 14:36:18.284 Tell The DJ[14955:c07] ERROR: Plugin \'Device\' not found, or is not a CDVPlugin. Check your plugin
I was using PhoneGap 3.0/3.1 and was removing the local build folder before rebuilding (since I had to copy icons and stuff in a secondary build script). This broke my plugins and produced this same error message.
In the end I found I had to remove ./plugins/ios.json
when removing ./platforms/ios
to make sure the plugins were rebuilt.