Apropos helps your site serve up the appropriate image for every visitor. Serving multiple versions of an image in responsive and/or localized web sites can be a chore, but Apropos simplifies and automates this task. Instead of manually writing a lot of CSS rules to swap different images, Apropos generates CSS for you based on a simple file naming convention.
Gemfile gem 'apropos', '~> 0.1.2'
install gem install apropos -v 0.1.2