Sinstagram was a back-end web development exercise, turned functional social network. Users are able to create accounts, make profiles, and upload and comment on pictures. It features a simple feed, a dedicated profile for each user, and a CRUD interface that allows users to add photos to the site, see other people's photos, update their information, and delete what they don't want to keep online anymore. This website is made by PHP and utilizes MySQL. 

You can use Sinstagram here