Sophiastra

Sophiastra is a note app that shows you what you don't understand yet. The name comes from wisdom (sophia) piling up like layers of rock (strata).

• Map: lay out your topics on a 3D map and see everything at once. The level below shows faintly underneath, so you notice unexpected connections.
• Layers: when a topic grows, dig into a deeper level inside it. Big subjects stay on top, details go deeper.
• Notes: inside each topic, keep writing chat-like bubbles in time order. Read them straight through like a book with Reader mode.
• 2D pyramid: switch to 2D to build your thinking from top to bottom (conclusion, reasons, evidence). Put questions like "Why?" or "For example?" on each row, and empty rows show you what you don't understand yet.
• Self-made quizzes: write your own true/false or multiple-choice questions, organize them in folders, and test yourself. Retry only the ones you missed.
• Team worlds: share one world with your team using an invite code. Changes appear on everyone's screen in about a second. Everything is end-to-end encrypted, so even the relay server can't read your notes.

Free, no ads, no account needed. Your notes are stored on your own computer, with automatic daily backups. A short voice-guided tour helps you get started in 5 minutes. Available for Mac (Apple silicon) and Windows, and you can try it in the browser without installing. Available in English and Japanese.