As described by Lifehacker.com: "Mangle is a handy tool for formatting your Manga and comic collections for easy reading on your Kindle. It includes page sorting, downsampling, and auto rotation for fuss-free reading."
The GIMP (GNU Image Manipulation Program) is a freely distributed program for such tasks as photo retouching, image composition and image authoring. It has many capabilities. It can be used as a simple paint program, an expert quality photo retouching program, an online batch processing system, a mass production image renderer, an image format converter, etc.
With DrawBerry, you have all the possibilities the vectorial drawing offers you in a free, easy to use and powerful application. If you don't need applications such Illustrator or Inkscape and you want to create some simple (or less simple) illustrations, DrawBerry is for you.