# What an open-source rival taught me

> I read all 70 releases of Dorso, the free Mac app once called Posturr, plus its issues and reviews. What it does well, and what I'm taking from it.

Canonical: https://poxture.com/blog/what-an-open-source-rival-taught-me
Last updated: 2026-11-04

Blog · 4 November 2026

Dorso is a free Mac app that blurs your screen when you slouch. I spent a day reading everything around it.

Shyam Verma

Dorso is a free Mac app that blurs your screen when you slouch. Tom Johnell built it in January, under the name Posturr, and renamed it Dorso in February.[1] A Hacker News post about it got 692 points and 223 comments.[2] Its GitHub page has over 2,600 stars.[3]

I make [Poxture App](https://poxture.com/), a posture app for Mac. It checks your posture through the camera too, so I wanted to know what people like about Dorso and what they ask it for. I spent a day reading its 70 releases, 112 issues and pull requests, the Hacker News thread and its App Store reviews.

## What Tom did well

1. He shipped what people asked for, fast. 31 releases in the first 8 days. On day 3 a user asked for a separate setup per monitor arrangement. It shipped about 2 hours later.[1,4]
2. He listened when people offered money. One of the first Hacker News comments was "I would pay $10 for this." 8 days later he put it on the App Store for $4.99 and kept the GitHub download free.[2,5]
3. He got it notarized fast. An early comment said an unchecked app that uses the camera was a "no go". About 4 hours later Tom replied that it was notarized.[2]
4. He cut CPU when users complained. On the day of the Hacker News post he cut it by about 80%. One user still saw 30 to 35% on an M1 Pro, so 3 days later he made a lower default, about 8% in his tests.[2,4]
5. He said no in public. Blink tracking and a nose-touch alert each got a short, polite no. In his words: "I'm weary of apps that slowly try to become the solution to everything."[4]
6. He credits people by name. His README lists 22 people, some only for suggesting a feature or reporting a bug.[3]
7. His site lets you try each warning style on the page itself.[6]

## What his users said

1. The nudge works. All 5 of its US App Store reviews give 5 stars. On Hacker News: "I am using it 10 minutes and I already hate it since it's too good."[2,5]
2. Some people can't work with a blur. "I share my screen all the time.. not going to happen." Tom added a red glow and a border on day 3, and a keyboard shortcut to pause it during screen shares on day 6.[2,1,4]
3. False alarms. Looking down to write, moving a laptop to a new desk, standing up. I count 6 issues about this, and 5 are closed.[4]
4. Sitting still. The open idea with the most reactions (8) is a stand-up reminder. One Hacker News reader quoted a doctor: "the best posture is the next one."[4,2]

## What I'm taking from it

1. Reply to every bug report the same day, and thank the person in the release notes (with their OK).
2. Talk more about "Sitting still too long". Poxture App already checks it, and I list it fifth.

To be honest, for a lot of people Dorso is the right pick. It's free on GitHub, and its AirPods mode works with no camera.[3] Its code is open if you want to see how a Mac app like this is built. I keep a side-by-side on our [Dorso alternative](https://poxture.com/alternatives/dorso-vs-poxture) page, including where Dorso is the better choice.

Have you used Dorso or Posturr? I'd like to hear what made you keep it, or turn it off.

## Sources

1. Dorso's GitHub releases page (v1.0.0 to v1.17.0; v1.9.0 "Posturr is now Dorso"), checked 4 November 2026.
2. [Hacker News, "A macOS app that blurs your screen when you slouch"](https://news.ycombinator.com/item?id=46754944), checked 4 November 2026.
3. Dorso's GitHub project page and README, checked 4 November 2026.
4. Dorso's GitHub issues (#13, #14, #16, #35, #38, #47, #55, #56, #79, #84), checked 4 November 2026.
5. Dorso on the Mac App Store (US), checked 4 November 2026.
6. Dorso's website, checked 4 November 2026.

## Want a nudge when you slouch? Poxture App checks your posture from the menu bar.

Try it on your own workday: an hour a day is free for good, and every feature works all day for your first 14 days.

Needs an Apple Silicon Mac (M1 or later) with a built-in camera or an external webcam, and macOS 15 or later.

Version 0.11.6 · released 9 November 2026

Poxture App is a Mac app. Open poxture.com on your Mac to download.

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## Related

- [Poxture App](https://poxture.com/)
- [Dorso alternative](https://poxture.com/alternatives/dorso-vs-poxture)