http://docs.smarthealthit.org/authorization/backend-services/
Note new addition of EPIC's SMART (FHIR) Sandbox to the Dev Book.
To go straight to your Apps in the Cerner SandBox: https://code.cerner.com/developer/smart-on-fhir/apps
... and please don't forget to share your notes in the FHIR Dev Document.
A wealth of documentation awaits us at http://docs.smarthealthit.org/tutorials/javascript/
FHIR Dev Book