This is more for myself, but if you ever get the following on Heroku

ActionView::Template::Error (blueprint/screen.css isn't precompiled):

The solution is setting the following in your confi/environments/production.rb

config.assets.compile = true

** The following will *NOT* work

RAILS_ENV=production bundle exec rake assets:precompile

** Also the Heroku post saying you set the above and then see (below) doesn't happen 

-----> Preparing Rails asset pipeline