Building webapps with Storyline2

I want to create an app with my storyline2 project.  I am trying to use https://build.phonegap.com/apps but when I try to upload the zipped file it says index.html not found.  I've tried renaming just about every file to index.html thinking maybe I was just changing the wrong one.  But I get the same results every time.  I want to make my project into an app that can be sold in the app store.  I want it to be a collection of centers for k-12 teachers to use in the classroom with ipads.  Accessing Moodle, another LMS, or even a website each time is too time consuming to be practical in a classroom.  Any advice on a simple solution is appreciated, I am not a web developer or programer so it needs to be simple.