LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Linked Ideas - A macOS/iOS apps to treat ideas as links of concepts.
BigHairyGoal - Get your ideas down and get insights on them.
Xmind - Xmind is a brainstorming and mind mapping application.
ClickCharts - Download ClickCharts free flowchart diagramming software to easily draw flowcharts and map out a visual representation of a data flow or other process.
vym - VYM (View Your Mind) is a tool to generate and manipulate maps which show your thoughts.