Design App is design as per OOPS concept. Used SOLID principles in designing app. Following are the classes in the app Model • FlickrImage - This class have Flickr public feed information. Network • FlickrFeedFetcher - This class request flickr server for feeds for provided url. • FlickrJSONParser - This class parses the json data received from flickr feeds Controllers • FlickrPublicFeedCollectionViewController - Collection view controller show images fetched from flickr public feeds. • FlickrImageTableViewController - This class will display the image and its meta data. Views • FlickrImageCollectionViewCell - Customized collection view cell contains UIImageView to show image. • FlickrImageDetailTableViewCell- Customized variable size table view cell contains UIImageView and image’s metadata.