Sinatra-datamapper-delayed_job-example is a project mainly written in Ruby, it's free.
Just an example howto use Sinatra 1.1 + Delayed_job 2.0.3 + Damapper
Example application for those, who want's to use Sinatra 1.1 with Delayed_Job (2.0.3) together with DataMapper.
To run it, follow these steps: