My feature phone is an LG Extravert, and I decided to experiment with the "Drawing Pad" application included with it. The Extravert isn't a smartphone, just a feature phone, running an OS called Brew MP.

The screen is 240x360, and the drawing pad canvas is fixed at 300x240. The most relatively comfortable way to draw on it is vertical (portrait), like its normal usage, but the canvas is fixed in horizontal (landscape).

Drawing Pad has only a simple pencil and a simple eraser, the screen has imprecise accuracy, and the app has bugs. I had to scratch out a word because the eraser tool broke itself when I received an SMS.

The pad really is smaller than a business card. The entire screen, including all controls, is 2.5 inches tall by 1.5 inches wide.