Implemented pull to refresh features, and fixed the check for a null Json object to use isNull().
Added a background color to images, so images will non-square aspect ratios look better.
Added photo header with user profile image and username.
Refactored JSON-parsing duty to Instagram and User from StreamActivity. Also fixed some minor warnings.
Added time with adaptive display of creation time, "yesterday", or the date, depending on when the photo was uploaded.
Formatted caption and added dummy views for like and comments
Added likes.