Drawing tablet

I use a Wacom Intuos graphics tablet when I am editing my photographs on the computer. This uses a pen-like instument on the special flat surface of a tablet to imitate the use of a pen or brush. It is pressure sensitive, allowing me to adjust the width or density of my brush strokes, and make controlled, fine adjustments to tone, colour, etc on selected parts of the picture.

However, the tablet is separate from the computer screen. How much better it would be if I could draw directly on the screen. Wacom do make such a device, and my daughter, who likes to use her computer for drawing, would love one - but they are expensive. As a substitute, she has found that she can use a soft tipped stylus on my wife's iPad with an appropriate drawing app. She has become quite skilled at it.