Waste of Time
The point of a free version of the paid app is to give users an ad-supported trial, show them what the app can do and tempt them to purchase the full version. This allows you to draw a font, then not save it or do anything with it. I have no idea what the full version of the app might be like. And as I had to watch an ad roughly every two minutes during this pointless experiment, I do not feel incentivised to find out.