Scapple is a popular mind-mapping and brainstorming tool developed by (the same creators of Scrivener). Unlike rigid mind-mapping software, Scapple is designed to be a "free-form" canvas where you can jot down notes anywhere and connect them with lines. Safe Ways to Get Scapple
If you want to use Scapple without the risks of pirated software, consider these official options: scapple-1-0-keygen
Another privacy-focused tool with an infinite whiteboard/canvas feature for connecting ideas. Scapple is a popular mind-mapping and brainstorming tool