To add the RTI cartridge to an application, from the management console:
These steps are illustrated below.
Application Page
 
After Add Cartridge, scroll down to Install Your Own Cartridge
Click Add Cartridge to Confirm Adding RTI Cartridge
 
View Details of Added Cartridge
 
Return to Application Page, see RTI Cartridge Shown
 
To add the RTI cartridge to an application named myApp, from the command line:
$ rhc add-cartridge http://www.rtiperformance.com/XXXXXXX/manifest.yml -a myApp
Password: ***************

The cartridge 'http://www.rtiperformance.com/XXXXXXX/manifest.yml' will be downloaded and installed
Adding http://www.rtiperformance.com/XXXXXXX/manifest.yml to application 'myApp' ... Success

 ocsystemsinc-rti-3.4.4 (RTI-3.4.4)
----------------------------------
  From:  http://www.rtiperformance.com/XXXXXXX/manifest.yml
  Gears: Located with jbosseap-6

RESULT:
Added ocsystemsinc-rti-3.4.4 to application myApp
Installing RTI Enterprise collectors...
Check for RTI license...
RTI License expires in 29 days.
Enable RTI...
Finding JBoss directories
JBOSS_DIRECTORIES = /var/lib/openshift/XXXXXXX/jbosseap
Enable RTI for /var/lib/openshift/XXXXXXX/jbosseap...
Finding Tomcat directories
TOMCAT_DIRECTORIES = 
Starting RTI cartridge
Check for RTI license...
RTI License expires in 29 days.