A controller is the entity that determines the purposes, conditions and means of the processing of personal data, while the processor is an entity which processes personal data on behalf of the controller. 

Socrative is a data processor acting on behalf of educational institutions -- who are the data controllers and have determined the means and the purpose of the processing of the data -- for any personal data provided by users of our web or iOS apps. 

Personal data entered into the Socrative app is inaccessible by Socrative and is only being processed for the functioning of the app.