RailsPushQueues
This project rocks and uses MIT-LICENSE.
You can easily use Resque and/or Sidekiq workers without change.
Set Iron configs
LINK TO iron config stuff, iron.json or ENV vars.
On Heroku, just add the IronMQ add on: heroku addons:add iron_mq
Register the workers
This is basically creating queues for each worker and setting your application as the subscriber.
rake queues:subscribe\[ImageConversionWorker,http://enigmatic-falls-123.herokuapp.com/queues/receive\]
To verify the subscriber was added, you can run:
rake queues:info\[ImageConversionWorker\]