I haven’t used the desktop app, just the iPad app, but InShort is more of a project management app than it is a charting app. It’s pretty comprehensive and can have somewhat of a learning curve if you’re not familiar with project management software. Their website describes it best, but I should also add that I have never found an app that solves what inShort solves. It’s almost like a combination of business process design and nested mind maps.

“inShort allows breaking a complex task into simpler ones and displaying their relationship on a diagram. From the resulting map of tasks, you can compose a detailed plan and start its execution, marking the progress in the application. Thus, the application provides everything you need for working with projects.”

Edit: I guess they came out with a diagramming tool to accompany the app earlier this year. https://apps.apple.com/us/app-bundle/inset-handy-diagramming...