The Jevons paradox says otherwise. As producing apps becomes cheaper, we will not be able to help ourselves: we will make them larger until they fill all available space and cost just as much to produce and maintain.
That's the incorrect application of the Jevons Paradox. We won't get bigger apps, we'll get more apps.
Think about what happened to writing when we went from scribes to the printing press, and from the printing press to the web. Books and essays didn't get bigger. We just got more people writing.