A] Cloudinary: Cloudinary is a cloud service that offers a solution to a web application's entire image management pipeline. It is used to easily upload images to the cloud. It automatically performs smart image resizing, cropping and conversion without installing any complex software. Also, integration of Facebook or Twitter profile image extraction in a snap,that too in any dimension and style to match your website’s graphics requirements. Add following line to your Gemfile: gem 'cloudinary' Add following line to config/cloudinary.yml development: api_key: //enter api key api_secret: //enter api secret cloud_name: //enter cloud name