The present invention allows clinical trial organizers to operate a platform for creating trial specific custom mobile applications at a price point that would not be possible if the application were created by programmers on a trial-by-trial basis. The invention shortens build time by creating a hierarchy of questions that changes the next question posed to the user based upon their answer to a previous question thereby reducing the number of questions the user must answer while providing the application creation platform with the detailed information relevant to a specific clinical trial. The platform uses a simulation builder that provides a test version of the application to the user mobile device during the application creation process thereby allowing the user to see the layout of the application as they progress through the building process. While building the application, the user can create a simulated version of the application in real time deliver the same to the mobile device of the user. The system creates a handshaking process that allows the user to create annotations and/or edits in the simulated application that are communicated back to the building platform. Changes made in the simulated application will affect the landing page the user sees when returning to the building platform. The system will collect usability data from a clinical trial application on a plurality of trial subject and trial organizer mobile devices. The system can measure variables such as time on page, misentries, and missed selections of icons to determine common trouble spots for users. That data may be used to redesign the interface or process flow of the application to optimize usability.