Doodlz turns your screen into a virtual canvas. Draw by dragging one or more fingers across the screen. Set your line color and thickness by touching the info button in the lower-right corner of the screen. The app options include a slider for line width and red, green and blue sliders for line color. Buttons at the bottom of the options allow you to use your finger as an eraser or to erase the entire drawing. At any point while drawing, you can shake the device to clear the entire drawing from the screen. Double tap your drawing to save it to your Photos album.
This app is from our book "iPhone for Programmers: An App-Driven Approach" (http://www.deitel.com/books/iPhoneFP)