CodeSync is a utility which live reloads asset pipeline assets in their running browser sessions, and an in-browser IDE which allows you to edit your pre-compiled assets (coffeescript, sass, etc) in the browser and save them to disk.

# config/initializers/code_sync.rb
if Rails.env.development?
  CodeSync::Manager.start(forked: true, sprockets: Rails.application.assets )
end

# Gemfile
gem 'code_sync', git: "git@github.com:datapimp/code_sync.git"

# asset manifest
#= require 'code_sync'
#= require_self

window.codeSyncClient = new CodeSync.Client()

Now when you change assets in the asset pipeline, they will be applied to the browser without refreshing.