Handwriting that syncs, and stays yours.
A notes app built around the pen — pressure, tilt and the weight of real ink — for iPhone, iPad, Mac and Android. Everything you write is encrypted on your device before it leaves it, so the service that syncs your notes cannot read them.
Android, early build. You can install it now and write on it: pen, fountain, marker, highlighter and eraser, any colour, adjustable width and pressure response, five smoothing levels, and PDF or image import to write on top of. The S Pen's side button erases while held.
Sync is not connected in the Android build yet — it keeps notes on the device only, and closing the app loses the page. It is an early build for trying the pen, not for keeping anything you care about.
On a Mac or any laptop, use the web app. It reads and edits the same notes, syncs live, and encrypts everything in the browser — nothing to install. Open Lumy Notes →
Download for Android · 3.0 MB, arm64, Android 8+
Your phone will warn about installing outside the
Play Store; that warning is correct and you should only accept it for
software you trust. Verify what you downloaded with:
sha256sum lumy-notes-0.2.0-arm64.apk
3d45bb82b6be0f2061e27ab7eff9c1494988fa6951ca19eda369e26ea266cc44
Native iPhone and iPad apps are in development; those require Xcode on macOS, so they are not built yet. On a Mac the web app above is the intended way to work.
Built for the pen first
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It follows the nib, not the frame
An S Pen reports around 240 times a second — far faster than the screen redraws. Every one of those samples is used, and the stroke is extended slightly ahead of the pen to cover the unavoidable delay between moving your hand and seeing light. The ink sits under the tip instead of trailing behind it.
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Pressure and tilt that behave like ink
Press harder and the line thickens; move quickly and it thins, the way a real pen lays down less pigment at speed; lay the pen over and it broadens for shading. Light contact still draws a clean line rather than needing a firm press.
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Smoothing you choose, not smoothing you fight
Five levels, from untouched to heavily calmed. Each one smooths hard while the pen moves slowly, where shake shows, and backs off as it speeds up, where lag shows instead. Small handwriting keeps its character; diagrams come out clean.
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Paper, PDFs and photographs
Import a PDF and annotate it by hand with the original left intact. Drop in images. Type where typing is faster and keep it on the same page as the handwriting.
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Pick up a word you wrote an hour ago
Lasso any part of a page to move, resize or restyle it. Strokes are stored as real curves, not pixels, so they stay sharp at any zoom and export as SVG.
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Offline is the normal case
Write on a tablet with no signal, edit the same note on a phone, and both sets of changes survive when they meet. Nothing is silently discarded to resolve a conflict.
What the sync service can see
Notes are encrypted on your device, with keys that only your devices hold. This is not a policy commitment that could be revised later — the server has no way to read your notes, including for its operator.
Visible to the server
- The handle you chose
- Your devices' public keys
- That a note changed, roughly how large the change was, and when
- Your IP address while you are connected
Not visible to the server
- Anything you write, draw or type
- Note titles
- Images and PDFs you add
- Any key that could decrypt them
No request logs are kept, so there is no record of which notes you opened or when you read them.
Encryption chosen for documents, not messages
A chat message stops mattering in a week. A research notebook does not — what you write today may still be sensitive in fifteen years, which is long enough for the assumptions protecting it to change.
So the keys protecting your notes are agreed using two independent methods at once: the elliptic-curve exchange in use everywhere today, and a newer one designed to resist quantum attack. An attacker who records your traffic now and breaks either method later still gets nothing, because they would have to break both.
Sign-in is by passkey, so there is no password to steal, reuse or phish — and no password database here to leak.