The pink, purple, fairy princess theme is very appealing to my daughter, she willingly plays this game.
She frequently touches the Home button causing her to have to start over. This is discouraging since she wants to see the picture at the end.
If you move that button and require users to touch it twice before losing their work, I would gladly upgrade to the paid version.
Sdlium about Math Dots(Fairy Princess): Connect The Dot Puzzle Game/ Flashcard Drills App for Addition & Subtraction