InAppSettings is an open source framework determined to remedy this situation once and for all by easily allowing developers to have the same settings in the Settings app in in their app. InAppSettings uses the same Settings.bundle so there is no duplication of files or work. Simply add InAppSettings to the app’s project and call it’s view controler from code or Interface Builder and you’re done!
iPhone InAppSettings library @ BitBucket (MIT License)
The is a another similarly sounding equivalent called InAppSettingsKit, which serves a similar purpose and is BSD licensed.