Obsidian is a tool for productivity that allows users to take notes and then link different thoughts into charts. You can choose to combine your input into a chart, with circles representing a different thought and lines joining related ideas; with links and backlinks, connecting two thoughts to each other; or with external links, starting with one idea and then developing others around it. With nearly 1,000 plugins and over 100 themes, you will also be able to customize your graphics in any way you want.