WonderPen is a writing app for both professional and amateur writers.

Features
- Tree view, drag-and-drop to reorder.
- An easy-to-use text editor that supports Markdown.
- Supports full-screen mode, lets you focus on writing.
- Docs can be exported as Image, PDF, Word, HTML, etc.
- Support whiteboard mode, in which you can add any note, table, kanban and other information.
- Auto save while editing. You can backup all docs as a single file and restore from it later.
- Add memo for each doc.
- Focus on one node of the doc tree.
- Search in all docs.
- Darkmode support.
- Data can be backed up automatically, and import and export are supported.