Part 1:
Api : http://www.androidbegin.com/tutorial/jsonparsetutorial.txt Fetch of images should be done through RxJava and Retrofit. Please note that the interview will be disqualified if you dont use these libraries Display of images should use Glide or Picasso or Fresco libraries. Please note that the interview will be disqualified if you dont use one of these libraries Make use of a recyclerview to display these images. The picture should become fullscreen on click and then when pressing back button, will go back to multiple images view.
Part 2 :
Give a button to extract the contact list of the user from the phone. Ask for "runtime permissions" for contact list access. Create a CSV format from the contact list. Do this task in the background using rxjava "observable". Please note that the interview will be disqualified if you dont use these libraries. Zip the CSV and save it in the storage of the user. When the zip of the CSV is completed and saved (all of this happens in background) - show a "snackbar" to the user informing him that operation has completed.