Looks fantastic! I love the combination of SQLite fixed schema with the hierarchical view.
Some advice on the website: Do some browser sniffing (I know) to display a screenshot of the software on the user's operating system. This immediately answers the question "Does the software work on my computer?"
Also, the source code link should be near the Download section. Not everyone is trained that the triangle GitHub icon in the top right means "source code".
The screenshot suggestion is a good one, whenever I open a GUI software page and see a screenshot of Windows or MacOS I often just close the tab and move on.
Some advice on the website: Do some browser sniffing (I know) to display a screenshot of the software on the user's operating system. This immediately answers the question "Does the software work on my computer?" Also, the source code link should be near the Download section. Not everyone is trained that the triangle GitHub icon in the top right means "source code".