Paintbook is a paint program by Seam M. Puckett and costs $4.99 in the iTunes store (iTune Link). Like all paint programs that I have tried, and I have tried many, Paintbook allows you to paint with your finger on your iPod Touch.
What makes Paintbook different is that it is vector-based drawing and not pixel-based. This means when you export the image you can put it into Illustrator or Photoshop and increase the size of the image without losing quality.
Paintbook is not the easiest paint program to get the hang of. In fact, it took me a while to figure it out. Once you do, it becomes a program that is limited by your patience and imagination. You have color controls, brush size and transparency controls, and an undo tool. There is not an eraser, which I think is a must in a paint program. Yes, you can make your brush white and erase, but I would like to see a dedicated eraser tool. It does have undo, but I still want that eraser tool.
If you don't want to change the size of your image when you export the painting, you can do it right in the program. Speaking of exporting, Paintbook will export your image in PDF or Jpg . JPGs can be sent to you iPhoto library and then sync with your computer.. You can then retrieve your image in iPhoto. You can also join Paintbook.ca and upload to your account and send a link for a downloadable pdf. Paintbook.ca is free.
If you don't want to export your image, you can store it in the app itself for adding to later, or just making a sketchbook in the program.