Was not able to find what was the framework used. Any ideas on what was used to package the code into ios app? Previous interviews mentioned they used Chromebo

Was not able to find what was the framework used. Any ideas on what was used to package the code into ios app? Previous interviews mentioned they used Chromebook and Nitrious.IO to work and develop the project but seems like something else needed to package the javascript or rails code into the ios app? Or maybe I am missing something