This app is the sample app for iOS Property Validation Built on KVC: http://blogs.captechconsulting.com/blog/john-szumski/ios-property-validation-built-kvc.
The app implements a gas price comparison app that relies on crowd-sourced data in the same vein as GasBuddy or other similar services. We chose this scenario because of the inherent unpredictability of user-generated data that makes validation an essential piece of the app. The app includes five stubbed out JSON responses that have various changes in the data that should be handled by the app.