In FlickrFetchr change ENDPOINT from http to https. Also uncomment PARAM_EXTRAS. Now app gets response.

Reference
http://forums.bignerdranch.com/viewtopic.php?f=423&t=8944
https://www.flickr.com/services/api/
http://www.forbes.com/sites/tjmccue/2012/05/15/why-has-yahoo-killed-flickr-5-alternatives-for-photo-sharing/