Startup Ideas Bank
A gimmick for reMarkable users that lacks a viable market.
AI roast score: 30/100 (F)
The idea
MaximeRivest/riddle — The diary of Tom Riddle for the reMarkable Paper Pro — write with your pen, the page drinks your ink and answers in a flowing hand
riddle — the diary of Tom Riddle, for the reMarkable Paper Pro
Write on the page with your pen. After a pause, the diary drinks your ink —
your words fade into the paper — the page thinks for a moment, and an answer
writes itself back in a flowing hand, stroke by stroke, then fades away.
No screen glow, no keyboard, no chat UI. Just ink appearing on paper.
This is the diary from the demo .
🪄 New to this? Start here
You need a reMarkable Paper Pro in developer mode with a launcher installed.
If that sounds like a lot, it isn't — remagic
walks you through turning on developer mode and sets up everything with one
command. Come back here, drop riddle in, and start writing to Tom.
Already have xovi + AppLoad? Install from the remagic
catalog, grab the prebuilt bundle , or
build from source .
Install with remagic (easiest)
remagic install riddle # checksum-verified download → AppLoad
remagic config riddle # settings form in your browser (+ QR for phone)
Then in AppLoad : tap Reload , then The Diary . Write, and rest your
pen. (Or install it from the Store app right on the tablet.)
Install the prebuilt bundle
Grab riddle-<version>.zip from the latest release
and unzip it into a folder: unzip riddle-*.zip -d riddle
Copy the folder to your tablet:
scp -O -r riddle root@10.11.99.1:/home/root/xovi/exthome/appload/
Add an API key: cp oracle.env.example oracle.env in that folder and put your RIDDLE_OPENAI_KEY in it (any OpenAI-compatible key). Or skip it to use pi .
In AppLoad : tap Reload , then The Diary . Write, and rest your pen.
⚠️ This modifies your device. The prebuilt bundle and the catalog build
run in takeover mode : tapping The Diary stops the whole reMarkable UI
and takes the screen. Leave with a 5-finger tap — xochitl restarts
automatically. It runs as root and drives the e-ink engine directly. It has
only been tested on a reMarkable Paper Pro (ferrari, aarch64,
OS 3.26–3.27). It may not work on other models or OS versions, and you use
it entirely at your own risk. Not affiliated with reMarkable AS. Keep SSH
access working before you install anything — if anything ever wedges:
ssh root@10.11.99.1 'systemctl start xochitl' .
How it works
pen (raw evdev, full 4096-level pressure, hardware event rate)
│ strokes
▼
riddle ── idle 2.8s → commit page → PNG ──► oracle (resident LLM process,
│ streams reply sentence-by-sentence)
▼ strokes (Dancing Script → skeletonized to single-pixel pen paths)
display backend
├── qtfb — windowed, inside xochitl (build-from-source flavour)
└── quill — full takeover: xochitl stopped, vendor e-ink engine
driven direct
The roast
This is more of a Harry Potter fanfic turned coding project than a viable business. The idea targets an extremely niche market - reMarkable Paper Pro users who also want a magical diary experience. The complexity and risk involved in modifying the device's operating system for this gimmick further shrinks the potential user base. When the biggest unknown is 'will_pay' (q15), this level of intricacy and niche targeting is a recipe for failure. The subscription model (q7) combined with standard pricing (q9) for such a specialized use case is highly unlikely to succeed. Without funding (q14) and being a solo founder (q13), the execution risk is magnified several times over.
Three red flags stand out: First, the technical complexity and risk to the user's device make adoption unlikely. Second, the market size is minuscule, limited to reMarkable Paper Pro users willing to modify their devices. Third, the lack of funding and a solo founder make it almost impossible to scale this to a meaningful business. In summary, this is an interesting experiment but not a viable business.
Red flags
- Technical complexity and device risk
- Extremely niche market
- Solo founder with no funding
Verdict
An intriguing project for personal satisfaction, but not something that will ever be a sustainable business.
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