A stylus-first PDF annotation tool, built for live math teaching.

Annotate any PDF (or blank page) with low-latency ink, a math-aware toolset, and a lockable side panel that stays out of the way. Open a lecture PDF, scribble a proof, drop a graph, and flatten it all back to a shareable file.

• Fluid inking — perfect-freehand strokes over Pointer Events, with palette, widths, dash styles, and a fading laser pointer.
• Math tools — function plotter with expression parser, implicit curves, LaTeX text, number line, shapes, protractor, and ruler.
• PDF + blank pages — mix, reorder, duplicate, and delete pages from a thumbnail strip.
• Undo everywhere — per-page history survives reorder, duplicate, delete.
• Autosave — sidecar JSON next to the PDF; reopen right where you left off.
• Presenter view — F5 for a clean fullscreen mode with quick navigation.
• Flatten export — bake annotations back into a shareable PDF.

Grab a prebuilt installer from the latest release:

Prereleases ship NSIS .exe only; .msi is stable-only.

A few favorites — the sidebar lists the rest.

• PLAN.md — design, architecture, and roadmap
• CONTRIBUTING.md — dev setup, workflow, and release
• AGENTS.md — contribution rules for humans and AI agents

MIT