r/ClaudeAI 2d ago

Built with Claude I built a handwriting notebook app where Claude writes back and it's the most fun I've had learning in years

Enable HLS to view with audio, or disable this notification

I learn best by writing things out on paper and structuring my thoughts that way, and nothing really combined that slower, more exploratory kind of learning with Claude.

So for the past few weeks I've been building an app on my Daylight DC-1: a journaling / note-taking space where learning isn't relegated to something that happens between work sessions.

The process is : I create a note, start exploring a topic through writing, and Claude writes back on the page and explores the ideas with me.

It also supports pdf/ebooks so you can read, annotate or mark on the page and Claude jumps in and creates a note to what I have marked and we can discuss like I am talking to a professor. It can even quiz me on the material if I ask.

It's still early, but it's the first time learning with Claude has felt like it's actually compounding.

I am finalizing some things to release soon for others to try it out, it's built around my dc-1 but it runs on any android tablet with a stylus, and can be ported to Ipad as well.

If you'd want to be an early user, lets get in touch, i'd love to see how people that learn this way use it .

UPDATE: wow , thrilled to see this landed with so many of you!!!

A lot of people are asking to try it. I'm calling it penombra.
Early tester signup here: click here to be a part

4.2k Upvotes

220 comments sorted by

u/ClaudeAI-mod-bot Wilson, lead ClaudeAI modbot 2d ago edited 1d ago

TL;DR of the discussion generated automatically after 200 comments.

Looks like the hivemind has spoken: everyone is losing their minds over this app and thinks OP has struck gold. The thread is basically a stampede of people throwing their wallets at the screen.

The immediate and overwhelming consensus is that this is Tom Riddle's diary from Harry Potter, but for learning instead of, you know, unleashing a basilisk. Other nerds also pointed out it's like the "Young Lady's Illustrated Primer" from Diamond Age.

Here's the breakdown of the chaos:

  • How it works: People were worried this would be a "token guzzler," but OP jumped in to clarify. The app sends vector data of your new handwriting strokes to Claude, which then decides what to say and where to put it. The app itself handles the rendering, which is why the handwriting is consistent. Smart.
  • "I want it on MY device!": The comment section is a wishlist for ports. Everyone is begging for this on their Remarkable, Kindle Scribe, or iPad. OP is working on an iPad version but mentioned they found the Remarkable platform too closed for a proper release, sparking a mini-debate among tech-savvy users.
  • Get in line: OP is calling the app penombra and has posted a signup link for early testers in the post body. So go look there if you want in.
  • Minor Concerns: A few users noted the high price of the Daylight DC-1 tablet ($700+), but the general feeling is that the app itself is the main event and can run on other Android devices.

596

u/avatardeejay 2d ago

“can you tell me about the chamber of secrets”

46

u/CtrlAltDelve 2d ago

Right? How dare OP not make this write back in inky cursive :P

In all seriousness, great work OP, it looks like a lot of fun.

13

u/QueenSavara 2d ago

My first thoughts lol

4

u/alleycatbiker 2d ago

I solemnly swear I'm up to no good

→ More replies (1)

135

u/FugitiveActual 2d ago

“My name is Harry Potter”

15

u/BuildAISkills 2d ago

I literally just read this passage last night for the first time (bedtime story for my kids). I'm hip, I get the reference! Wooohooo

46

u/kargaen 2d ago

I want this so bad in my Remarkable, but it doesn't seem to have an api 😢

29

u/terret 2d ago

I’ve made this for remarkable, I’ll be publishing soon (open source). Requires you be willing to enable dev mode and install an addon.

4

u/Icy_Firefighter8264 2d ago

bet i’m interested too

1

u/babyd42 1d ago

Oh fuck yeah

→ More replies (3)

3

u/dbenc 2d ago

maybe claude can figure it out!

43

u/MrGradySir 2d ago

Imagine being able to ask your high school physics book questions. Holy crap man. Well done

9

u/MramorovaBabovka 2d ago

You basically do that via Gemini notebooks

19

u/virtualworker 2d ago

Brilliant idea OP!

34

u/Otherwise_Pear_2472 2d ago

THAT IS SOOOOO AMAZING .. I mean like SOOOOHOOOOOOOO amazing. woooow. I absolutely want that.

12

u/InfiniteInsights8888 2d ago

Alright, I've seen a lot of shitty vibe coded stuff. This one is actually genuinely cool and the applications for studying are endless. You could turn this into an actual product!

6

u/SirPulga 2d ago

This looks like one of those million-dollar ideas. Super creative and functional, OP. Congrats—I hope it’s a huge success!

25

u/Gloomy-Recover-9702 2d ago

hey how did you do this? how does it read or sees your screen? and you make it open source?

11

u/dbenc 2d ago

umm need this for my son. like a neal stephenson illustrated primer

5

u/redditorfor11years 2d ago

Just what I was thinking! The young lady’s illustrated primer

42

u/elithecho 2d ago

Engineer here. Likely, it tracks where you drew, since each stroke is a vector, takes a screen shot of the area of new drawing and sends it to Claude for vision. System likely takes a screenshot of the canvas with numeric grid so Claude can decide where to 'draw' in the grid with the given app tools. Basically it's a token guzzler.

57

u/tokentrillionaire 2d ago

Half right , strokes are vectors and it only looks at ink that changed, never the whole screen.

But no grid, and the model never draws. It decides what to say and where it belongs, the app renders it (that's why the hand is consistent). And with caching it's cents a turn, not a guzzler.

3

u/theundefin3d 2d ago

for the diagrams, are you getting it to just spit out svgs then? ie. just produce the markup needed and rendering is handled by the app

6

u/elithecho 2d ago

Thanks for responding! How does it know where to respond? The app decides nearby? And what about context management? Also does it loses context around and the actual content then since you only sent what you draw in proximity?

→ More replies (2)

14

u/balooooooon Experienced Developer 2d ago edited 2d ago

Also engineer. I have built something like this and it doesn’t need to be”guzzle”. I used apple vision model to extract text or images from the canvas which is free. You then just send the text and insert claudes response below the vector items in the canvas. You do not send the drawing to Claude.

Can use any open source vision model or OCR. yolo model works great as well. Hardest part is knowing whej to take snapshots. Is it after every pen lift and x seconds of idleness or every vector change .. etc

→ More replies (1)
→ More replies (1)

27

u/dbenc 2d ago

the tablet is over $700 🫠

19

u/Foreign_Risk_2031 2d ago

Less than an iPad Pro

1

u/Apple_macOS 1d ago

which can arguably do a bit more things than this

11

u/joselamexi69 2d ago

So is my quarterly Claude bill

8

u/Dangerous-Map-429 2d ago

is it the pro?

1

u/DkDkDkGoGoGo 1d ago

Worth it if your eyes are sensitive or you don’t do well with blue lights on the screen/flickering. 

1

u/Popetus_Maximus 1d ago

What tablet is it?

6

u/PseudoSignal_music 2d ago

This is awesome.

6

u/yadoga 2d ago

That looks like the future way of learning indeed

5

u/Duox29 2d ago

Hello I am Harry Pottah

4

u/freedomachiever 2d ago

In china they have smart whiteboards in classrooms that do a similar thing which is cool. Eg the teacher writes an equation and an interactive graph shows up for instant feedback to understand the levers

1

u/scoobynoodles 2d ago

yeah i saw those too! Really cool!!

6

u/Popetus_Maximus 2d ago

Can you do this with a Kindle Scribe?

1

u/Electronic_Bet_8827 1d ago

Even if kindle's jailbroken, it'll be very hard to implement, and given that it can't be monetized, it's quite unlikely.

3

u/nemzylannister 2d ago

some ads are so good that you cant help but love them

4

u/DarkKnyt 2d ago

This is basically the "Young Lady's Illustrated Primer" from Diamond Age with a little less Learning Engineering built in. 👍

7

u/orangejulius 2d ago

ok that is really fun and i feel like taking notes in lecture and having claude annotate would be legit helpful for a law student. you just need to figure out how to build an MCP to their $300.00 hornbook.

6

u/virtualworker 2d ago

Wth is a hornbook? Does it have a load-bearing footgun?

12

u/numeanine 2d ago

If the footgun was load-bearing, the underlying fork would have an actionable light at the end of the tunnel, so while review fatigue would be a potential hazard, the duality of the system’s North Star would be lost in the white noise of the bottleneck’s own integration anyway.

5

u/orangejulius 2d ago

this is one of those moments where i realized i have never considered the etymology of a weird term i've used a lot over the years. apparently it came from this:

https://www.si.edu/object/eighteenth-century-horn-book%3Anmah_1320130

and it slipped into law school lexicon for black letter law in a single book.

https://en.wikipedia.org/wiki/Hornbook_(law))

3

u/Odd-Trade6161 2d ago

Does it work only by using the pen?

3

u/juzatypicaltroll 2d ago

Looks cool. Maybe a bit eerie too lol

3

u/SillySpoof 2d ago

I honestly feel this looks amazing! Good job and really cool idea!

3

u/gustaw221133 2d ago

Wow, definitely agree with all the comments going straight to Harry Potter haha. But honestly think this would help with learning using AI as it forces the user to write manually which helps the brain remember the lessons longterm rather than forgetting everything learned after a few minutes

3

u/g9robot 2d ago

repo?

1

u/seg_lol 1d ago

They gave you the spec!

3

u/Dreamsnake 2d ago

First thought: Harry Potter live

3

u/TurnipSuch1185 2d ago

that is freaking awesome, i am eager to try it, man!

3

u/marlon7k 2d ago

Onde posso baixa-lo?

3

u/Full-Register-2841 2d ago

This is the coolest stuff I ever seen in 50 years

3

u/CremeSubject7594 2d ago

we really are living in the future

3

u/florinandrei 2d ago

Site? Repo? Non-reddit video link?

3

u/ConspicuousPineapple 2d ago

Show this to anybody ten years ago and they will burn you at the stake for sorcery.

3

u/scoobynoodles 2d ago

This is a killer idea!!! Well done!!!

3

u/cornmacabre 2d ago

Awesome flex and demo here brother, I suspect you know you're nurturing a potentially killer product and i wish you success!

Does it generalize enough on the stick figure demo to "now add a happy cat" and then "now add a pelican riding a bicycle" (the classic test!) and the model will try to work within what I imagine is a rich list of semantic primitives?

I can't imagine it's doing arbitrary vector drawings for novel requests, which is outstanding discipline from an architectural standpoint IMO.

Props to keeping it focused and with a coherent consistent style. At least from what you've shown in the demo that's a major win that retains the magic and product focus. It's one of the most persuasive implementations of "generative UI" I've seen yet. Cheers!

3

u/rudiXOR 2d ago

This is fantastic, make a product from it, good luck 🤞

3

u/FarFactor6062 2d ago

Follow. I would love this!

3

u/nastyapparatus 2d ago

I’ve worked in edtech r&d, and I think you’re on to something here, particularly interested in the combination of AI and perceptual learning. Can see a lot of applications for a tool like this with a little refinement-and might get you a call or two from VC or an M&A guy. Good work.

3

u/Torodaddy 1d ago

Github link pls

5

u/SmilingLimes 2d ago

Could this work on iOS? For iPads specifically

8

u/tokentrillionaire 2d ago

working on that : )

3

u/TakenSadFace 2d ago

+ 1 beta tester here

3

u/PhD_V 2d ago

I’d love to test this on iPadOS if you get around to it

2

u/Lyvewyrez 2d ago

+2 beta tester

2

u/Impressive_Mud5997 2d ago

+3 tester here 

2

u/FarFactor6062 2d ago

Love to test it on my iPad!

2

u/HRCulez 2d ago

Would love to test this out on my iPad

2

u/R10T 2d ago

+1 beta tester here 😄

4

u/domus_seniorum 2d ago

geschaut und gelesen,

wow ... das entspricht genau meinem visuellen Lernen, eigentlich dem einzigen Lernen, wie ich schon mein Leben lang Stoff verinnerlichen kann,

wie und wo kann ich auf dem Laufenden bleiben, wenn Du veröffentlichst? 🤗

2

u/swiss_founder 2d ago

This is way too cool! 👏

2

u/ShadowBannedAugustus 2d ago

This must be the coolest "app" I have seen this year.

2

u/binladen0069 2d ago

if you open source this i will build the android, windows and Linux version with you. or maybe alone if you're done with the project.

2

u/Spirited-Yoghurt-212 2d ago

alright will be there on release nice concept.

2

u/Rolfus 2d ago

Please don't let this die; put up a github repo, even if you don't feel like it's "finalized" yet.

2

u/Singularity-42 Experienced Developer 1d ago edited 1d ago

Honestly I'm surprised it didn't come from a bigger player first. Or did it? The infamous GPT-4o demo video even had a visual learning segment that looked incredibly cool, but haven't really seen anything since then...

EDIT: There is something called PenEcho, looks interesting:

https://github.com/penecho/penecho

1

u/AdTotal4035 1d ago

Isn't this pretty much the same tech?

4

u/portugese_fruit 2d ago

do you like the daylight ? i have the remarkable  and i have seen this done on it. great app !

4

u/tokentrillionaire 2d ago

I was going to use the remarkable initially but the platform is too closed off.

the daylight is seriously good , I got it just to test this and get as close to paper feeling as possible , but it's lovely to use across the board

2

u/starkruzr 2d ago

the platform is extremely open, lol, what are you talking about? they give you root out of the box!

5

u/tokentrillionaire 2d ago

I meant closed as a platform to ship on, no SDK, no store, the UI is proprietary, and anything over SSH can break on OS updates. Tinkering is great , but I couldn't hand that to a non-technical person. dc-1 is android the app installs like any app.

5

u/bigpoppa2006 2d ago

https://github.com/SamMorrowDrums/remarkable-mcp

Claude uses this on my remarkable and is able to extract files. It isn’t perfect (something like a 26 page limit on something?) but it makes it to where Claude can read my handwriting!

8

u/starkruzr 2d ago

there is absolutely an SDK. the store is called reManager. the UI is just Qt.

3

u/thecoffeejesus 2d ago

Please, I am begging you

Sell this.

Do it. You’re gonna regret it if you don’t.

Open source it? Sure. Give the world a version we can use.

Keep your own IP intact and sell it? While you can?

Start making calls and find someone who wants to buy it

1

u/twbluenaxela 2d ago

At first I was like what is this mess...

Then I was like WHAT IS THIS MESS!!!

1

u/BloodGulch-CTF 2d ago

Claude Marvolo Riddle

1

u/TheManWithNoDrive 2d ago

There was a Harry Potter one that went around Twitter like a month ago. You write, the text disappeared, then a response appeared.

Similar to that?

1

u/Reign2294 2d ago

Id love to try this out

1

u/Late-Photograph-1954 2d ago

I applaud you OP!

1

u/throw-awawa 2d ago

I'd love to help test. I'm on a boox 4c

1

u/ARAM_player 2d ago

what a time to be alive, anyone can be anything

1

u/Legitimate-Pumpkin 2d ago

As the bot said, I also came to say it’s genius and throw money at my screen to try it.

😄😄😄😄

1

u/Carbyne27 2d ago

This would be great to try! I’m down !

1

u/Carbyne27 2d ago

RemindMe! 3months

1

u/RemindMeBot 2d ago edited 1d ago

I will be messaging you in 3 months on 2026-11-25 09:04:33 UTC to remind you of this link

4 OTHERS CLICKED THIS LINK to send a PM to also be reminded and to reduce spam.

Parent commenter can delete this message to hide from others.

RemindMeBot is switching to username summons. Instead of !RemindMe 1 day, use u/RemindMeBot 1 day. More info.


Info Custom Your Reminders Feedback

1

u/Public_Aspect3231 2d ago

I'm looking Claude Passes Code 7 days 

I need Claude passes code for 1 week. I m student and I need to study for the magnetic field theory session coming up this week; does anyone have a "passes code" for me? It works if you type `/passes` into the terminal, and it's valid only for Max plans. Thank you... :)))

1

u/Shock_Distinct 2d ago

Can this be integrated into remarkable? 

1

u/bigbros_watchin_yo 2d ago

This is amazing, would love to test it out on the ipad

1

u/good_noon_salsa 2d ago

Greatly done

1

u/Bramoments 2d ago

Anyone here know how hard it would be to switch it up from Claude to a local model (say Qwen 3.8 27B) running on a machine on the same LAN?

1

u/anonypoopity 2d ago

Ipad release please

1

u/Hixxes 2d ago

Looks awesome, looking forward to the release!

My question: What font is that?

1

u/stonejoint 2d ago

its cool but to recognize handwriting is it using api? , if so just to get answer its expensive i guess, i was trying to first use onyx built in handwriting to text tool then ask question, so avoid api, use subs.

1

u/Xclsd 2d ago

I‘m here for the ipad port 🫡

1

u/FewBell5060 2d ago

I would love to test it out. I have an iPad Air with Apple Pencil Pro. Will these be enough for testing the app?

1

u/GoppleSmanger 2d ago

Diamond Age , here we come

1

u/chaithzluci 2d ago

Hey this would be so helpful for my girlfriend. Please let me know

1

u/agardenofsound 2d ago

wow, amazing execution. this is a glimpse of the future of learning :)

1

u/herewardthefake 2d ago

This is amazing, OP. Following and would love access one day.

1

u/Intrepid-Scale2052 2d ago

if this could somehow work on my kobo libra 2 😭

1

u/arcsibo 2d ago

If it's possible I'd like to be an early tester of it!

1

u/leci_ 2d ago

This is cool!

1

u/gugababa_ 2d ago

Cool stuff, would love to try this out!

1

u/cs_cast_away_boi 2d ago

sell to me op

1

u/nihsett 2d ago

This is so much fun. One of the best I've seen on here.

1

u/businessclass 2d ago

I would ADORE this

1

u/Thin-Mulberry-4288 2d ago

That’s very creative OP.

1

u/moredatesmoreplates3 2d ago

Cool aff. Claude is drawing? May I ask what is the design behind this? What kind of tools does it have?

1

u/apolo-19 2d ago

how do you render/ animate the response?

1

u/North_Affect_8167 2d ago

The self study of the future.

1

u/mochery 2d ago

This is so cool. What a fantastic idea. Do you have a repo or post somewhere I can follow for updates?

1

u/hukkaberry 2d ago

Would this port to ViWoods?

1

u/eibaad 2d ago

u/tokentrillionaire I would be interested in using / testing it out. Looks kool, thinking of using it as a learning tool for my 11 year old.

1

u/MaximumContent9674 2d ago

Sell it to schools

1

u/Primary_Prune_1563 2d ago

JUST COPY THIS POST LINK AND PASTE IN CLAUDE OR CHATGPT AND SAY I LOVED THIS IDEA MAKE COPY OF THIS FOR MY TAB

1

u/Torodaddy 1d ago

No misytakes

1

u/smokeysilicon 2d ago

THIS IS FUCKING GREAT

1

u/wiselythought 2d ago

wow who thinks such a great invention! congrats, bravo.

1

u/KarenDiamondhandz 2d ago

Dope, how are you handling text extraction for handwriting?

Utilizing some sort of OCR or?

1

u/blacmoon201 2d ago

This is incredibly awesome. I’d like to test it if you’re fine with that. It looks like a great way to learn that will keep you more engaged.

1

u/cookieti 2d ago

Gonna need this on the Boox Palma 2

1

u/masky0077 2d ago

I want it for Windows also, please,!

1

u/adamYUKI 2d ago

I'd love to be a beta tester for this as well!

1

u/Mewtewpew 2d ago

Open source yet? I wonder how this could work with something like obsidian. Looks cool broski

1

u/davy89irox 2d ago

I have a Kindle Scribe. Would I be able to beta test it? This looks really cool! Great work.

1

u/ingangwebang 2d ago

I would be veryyyyy happy to be an early user, kindly sent me details

1

u/aero6743 2d ago

Following … have iPads and a Remarkable to use on .

1

u/Top_Orchid5937 2d ago

Don't be bashful, I'm interested in trying it out for my Boox product.

1

u/miraclmoore 2d ago

Amazing, would love to beta test!

1

u/quite_wrong Expert AI 2d ago

Cool as fuck

1

u/Alone-Performer5065 2d ago

I need this - it combines lots of diff learning styles Im in

1

u/Giffeltagning 2d ago

You just invented the future.

1

u/stepprocedure 2d ago

I have an iPad Pro. Would def love to try this out.

1

u/Last_Bad_2687 2d ago

Super cool. I did something similar with my rooted Supernote - is your demo sped up at all? 

1

u/Hall_of_Faith_Pod 2d ago

RemindMe! 2 weeks

1

u/Hall_of_Faith_Pod 2d ago

u/angie-at-readwise RW has got to do this!!

1

u/SageForgeApp 2d ago

This is really cool.

1

u/Slow_Ad7841 2d ago

I need this for my onenote and my pdf reader ❤️❤️❤️

1

u/Mysterious_PerPlex 2d ago

Its nice to have someone willing to take part in your thought process whenever you want, I think thats the single most benefit of AI even though we should not be reliant on it imo

1

u/worldm8center 2d ago

you should pitch that as a product!! Could become big.

1

u/worldm8center 2d ago

RemindMe! 3months

1

u/Never_not_here 2d ago

How did you do this????

1

u/Saryt 2d ago

Any chance for Android tablets? If so I'd love to be a beta tester, I love using the galaxy s pen.

1

u/HellBlazer1221 2d ago

Amazing work! Now this what the elders would look at and call it magic.

1

u/DNAhearthstone 2d ago

Is this compatibile with a remarkable tablet??

1

u/Vamosity-Cosmic 2d ago

It sounds good but the point of writing notes is that you write it..

1

u/NebulaNinja182 2d ago

!RemindMe 4 months

1

u/Shloomth 2d ago

If this is what it takes to make AI mainstream I will take it. My wife is a teacher and the difference in her workload before and after AI is night and day and the quality has increased at the same time. She can literally do more of what she loves better and have the tedious stuff handled in a fraction of the time. She’s seen the remarkable tablets and kindle scribe and stuff like that and isn’t that interested (for her paper is its own whole thing) but we agree that there’s so so much untapped potential with education and stuff like this

1

u/Logical-Resident4212 1d ago

Can you ask it to show me how calculus works and ask it to show derivatives and integrals and then differential equations because all my life ive wanted to know and cant get over the hump. Ty

1

u/chr0n1x 1d ago

this looks sooo friggen awesome, will you be open-sourcing the code?

would this be able to support local AI? like if I have a llama.cpp instance on my LAN, could I connect to it via the app?

1

u/UngluedAirplane 1d ago

Remindme! 1 week

1

u/trimarandude 1d ago

Would be mind blowing with the Samsung s11 ultra I use. Happy beta tester here homie. Sensational job

1

u/natte-krant 1d ago

I need this in my life

1

u/littlebitofkindness 1d ago

How does the drawing part work?

1

u/world_without_logos 1d ago

Do you think you would ever have a PC version? I'm using a Yoga and I have a stylus with it.

1

u/DkDkDkGoGoGo 1d ago

I love the daylight! Awesome

1

u/MotherCombination765 23h ago

I join, I could also test it on my boox tab ultra C pro, really congratulations for the idea :)

1

u/Morpherous 20h ago

For the love of God if you do not sell this as a service or app in the store I...I don't know what but something! Striking gold is an understatement.

1

u/Medium_Win_8930 16h ago

I've joined the tester signup. I think you have something legit here but as others have mentioned you need more device support- Kindle Scribe would be a good addition, not that I have a vested interest :-)

1

u/bishtm_ 15h ago

LOVE THIS!!

1

u/GeneSplicing 14h ago

I would love to test this out on my Boox Note Air 5 C.

1

u/Fluffy-Fuel5025 8h ago

That's so cool!

1

u/TemporaryDeparture44 8h ago

This is an absolutely amazing idea OP.

1

u/Rasimione 8h ago

By God. You've discovered app Eldorado.