In OpKey, Robotium specific keywords are plug-in specific keywords. Test scripts created with these keywords can be executed by only using specific plug-ins. For example, Robotium specific keywords can only be executed by the Robotium plug-in.
Some Robotium specific keywords include: LaunchApplication, ClickOnButton, ClearEditText, ClickOnImage, and many other keywords.
For detailed information on Robotium keywords, please refer: Robotium Specific Keywords