Scapple is mind mapping software from Literature & Latte.
Mind Mapping is the art of exploring ideas through the use of boxes, line arrows, etc. The idea is to flesh out all of the parts of something by allowing the ideas to come to you as you see them visually connected.
It is a very powerful tool to help a writer get organized.
I use this to flesh out ideas around who a character is and how they are connected to others. I’ve also used it to connect plots, themes and other ideas. I have found it useful in world building to get a large picture idea of how all of the elements of a world are going together.
You can zoom in or out.