That's how drawing apps like Concept and Infinite Painter are priced. Free download, no sign up, several good features in the basic version. There are IAPs to

That's how drawing apps like Concept and Infinite Painter are priced. Free download, no sign up, several good features in the basic version. There are IAPs to unlock brushes and other things, and a small fee to buy everything. I believe I paid $15 one-time to get everything for Infinite Painter.