Books, audio, notes, flashcards, and sketches everything private and for you.
What's inside
Read, listen, write, study — without switching apps.
EPUB and PDF. Six themes. Full typography control.
MP3 and M4B. Chapter nav. Variable speed.
Markdown and LaTeX, rendered live as you type.
Spaced repetition. Build decks from notes or import.
Infinite Excalidraw canvas, beside your library.
No accounts. No tracking. Stays on your machine.
E-Reader
EPUB and PDF. Six hand-crafted themes. Type, size, spacing, all yours.
Audiobooks
Drop in MP3 or M4B. Chapters auto-detected. Resume where you stopped.
Flashcards
Spaced repetition built in. Decks from your notes, or import your own.
The formal definition of a limit:
if for every ε > 0 there exists a δ > 0 such that whenever |x − a| < δ it follows that |f(x) − L| < ε.
Notebooks
Write in Markdown. LaTeX, code blocks, and headers all inline.
Sketchbook
Diagram, annotate, map ideas, without losing your thoughts.
Analytics
Daily reading time, streaks, and a 12-week heatmap.
Six Built-in Themes
Sepia, light, moss, dark, cherry, sunset — or follow the system.
Availability
macOS
Windows
Linux