This program, once installed on your Mac is more or less an identical copy of Paint for Windows, also known as MS Paint, a lightweight application, that's really simple and has just enough options to edit an image, and that's it. With this tool we will be able to draw, crop, rotate, enlarge and reduce, and draw geometrical forms. It will also be able to write text.
As a simple program that it is, PaintDS doesn't support layers, or brushes or anything similar. All you can do is select the color, the tool you want to use and draw.
Just like its equivalent for Windows, PaintDS can come in very handy to resize images, crop areas and include a text, because thanks to its simplicity, it does all the latter very quickly, but for any other modifications, you will need a more advanced software.