1)Please put f_one.json file inside device internal storage's root directory.
2)Image Urls given inside the input file doesn't have good aspect ratio. So, images gets distort while resizing and display them on image view.
I have used Picasso open source library because of the following:
a)Handling ImageView recycling and download cancelation in an adapter.
b)Complex image transformations with minimal memory use.
c)Automatic memory and disk caching.
Additional points covered are:
a). Follow MVC architecture
b). Non UI blocking Code
c). Image Caching
d. Good workflow with version control system . (Frequent and meaningful commits pushes , feature branching etc.)
e). Meaningful documentation .
f). Memory Management