Workflowy

Workflowy is a productivity application designed for note-taking, list-making, and task management. It allows users to capture ideas, organize information with infinite nesting, and manage activities using features like Kanban boards and global search. The app syncs across devices and offers simple document sharing.

Workflowy is a note-taking and outlining application that allows users to organize information in infinitely nested lists. It supports capturing notes and ideas, organizing them, and sharing them. While it doesn't explicitly mention 'side notes' in the Tufte-style, it does allow for detailed organization and contextual information within its hierarchical structure. It also supports embedding various media types and offers public sharing of content.