Still in the works, but easy to install if you want to try. Add the following to your Gemfile:

gem 'padrino' # Padrino needs to be loaded first!
gem 'padrino-rpm'

Run bundle install and add a newrelic.yml to your project:

newrelic install "my-app-name"

If you are running your Padrino application on Heroku's Bamboo stack, running "newrelic install" is not necessary because Heroku adds newrelic.yml on your behalf.

If you are using unicorn, make sure that you read the following: http://newrelic.com/docs/troubleshooting/im-using-unicorn-and-i-dont-see-any-data

At the moment, this works for me. Any additions are welcome.