From Kalio Doodler:
Doodler is a natural drawing software. A pressure sensitive pen/tablet is required to use with Doodler. The user can use Doodler to draw, paint, illustrate, sketch, and doodle. The interface is simple enough that anyone can learn it under 10 minutes. The file formats supported are JPEG, PNG, BMP, and TIFF. Multi-layer feature enables the user to work efficiently. Popup reminder dialog every few hundred strokes.