Hey GT!

So my camp NaNoWriMo (national novel writing month) project is to write about these two kids who are coding an app together very similar to Tumblr. Basically an app of a live feed of videos, pics, etc. Does anyone know how I could describe the innards of coding for this in layman's terms? Like certain vocabulary, steps, etc? It's a YA novel so I don't want my readers to be overwhelmed with tech speak and either the things I look at are too complicated or skip the steps. I know they would write "psuedocode" and sketch out the interface but past that I'm stuck. Halp?