Penmentor

Claude marks up your handwritten math like a teacher

29Rank on 21 October 2026New on 21 Oct

Penmentor launched on 20 October 2026. It ranked #29 on Daily Launch on 21 October 2026 with a Launch Score of 54, from 60 points on Show HN. It was new in the ranking that day.

Visit site#4 on Show HN the day before · 60 points

I study calculus with a pen tablet in xournal++. I kept screenshotting my work into Claude and reading long answers back, when what I wanted was a teacher looking over my shoulder: circle the mistake, tick what's right, nudge me toward the next step, and show me why. penmentor is that, one key away, on my own Claude subscription.

From its README on GitHub

Penmentor is a launch on Show HN. It is written in Python and released under the MIT license.

Launch timeline

20 Oct15:10 UTC
Show HNPosted on Show HN
21 Oct07:26 UTC
Show HN60 points, ranked #29 on Daily Launch

Launch Score, last 7 days

Ranked on one day so far: 54 of 100 on 21 October.

Facts

Category: Other
Launched: 20 October 2026
Language: Python
License: MIT
Stars: 68
Sources: Show HN
Launch Score: 54 of 100

How the score works

Counted signal: Show HN: 60 points
Within its source that day: Beats 71% of launches
Against “strong” (300): 20%
Source weight: × 1
Base score: 45.7
Extra sources: None
First day ranked: +8
Launch Score: 54 of 100

How we rank

Sources

Show HN 60 points

Data as of 07:26 UTC, 21 October 2026.

For the maker

Best rank so far: #29 on 21 October 2026. Add this badge to your README or site; it shows the best rank and updates when that improves.

Markdown

[![Ranked #29 on Daily Launch](https://dailylaunch.org/badge/penmentor.svg)](https://dailylaunch.org/p/penmentor?ref=badge)

HTML

<a href="https://dailylaunch.org/p/penmentor?ref=badge"><img src="https://dailylaunch.org/badge/penmentor.svg" alt="Ranked #29 on Daily Launch" width="250" height="54"></a>

What is Penmentor?

Launch timeline

Launch Score, last 7 days