index.html.erb

<%# This would go into views/welcome/index.html.erb %>
<%= setup_context :title => "Home", :suppress_breadcrumb => true %>

<div class="row">
  <div class="col-md-12">
    <%= render_aspace_partial :partial => "shared/flash_messages" %>
  </div>

   <div class="col-md-12" style="padding: 30px;">
      <h1><%= I18n.t "welcome.heading" %></h1>
      <%= say_meow %> 
    </div>
</div>

plugin_init.rb

# A simple way to add helpers via a plugin
# this could be broken out in several way...
# for example, you could put the CatHelper in its own file an require_relative to that file
module CatHelper                                                                        
    def say_meow                                                                          
      "<b>meow</b>".html_safe                                                             
    end                                                                                   
end                                                                                     
                                                                                          
# here we reopen the ApplicationController ( after Rails has started )
# and stick in our helper module.
Rails.application.config.after_initialize do                                            
    ApplicationController.class_eval do                                                   
      include CatHelper                                                                   
      helper_method :say_meow                                                             
    end                                                                                   
end