Polyfillrb 
A simple ruby wrapper for the phenominal Polyfill.io Service by FTLabs for Rails applications.
How to use
The library provides a simple view helper to load in the polyfills. Simply in any view file add the polyfills call. Make sure to load it prior to running any other javascript. Here's an example app/views/layouts/welcome.erb:
<html>
<head>
<title>Welcome</title>
<%= stylesheet_link_tag 'application', media: 'all' %>
<%= csrf_meta_tokens %>
</head>
<body>
<%= yield %>
<%= polyfills %>
<%= javascript_include_tag 'application' %>
</body>
</html>
Installing
Add the gem to your Gemfile: gem "polyfillrb", "~>1.1.0"
Future Plans
- Cache polyfills to avoid node IO calls (especially in production)
- Ensure we are doing the most performant javascript executions.