For writers growing on Substack and LinkedIn

Keep showing up between essays.

New readers find you through what you post between essays. Pennywurth turns each essay into a month of posts in your voice that lead back to your newsletter. You approve each one, and Buffer publishes it.

Your first essay is free. Nothing posts without your OK, and we don't train on your writing.
Why growing is hard

Sharing an essay once isn't enough.

  1. You spend a weekend on an essay, share it once, and by Monday nobody sees it.
  2. Turning it into posts takes an hour or more each time, so it doesn’t happen.
  3. AI drafts sound like someone else, so you end up rewriting them.

Pennywurth writes those posts for you, in your voice, and plans them across the month. You read them, approve them, and get back to writing.

Your month

What your readers see between essays

How often do you publish an essay?
On your own26 quiet days after the essay
With Pennywurth11 new posts before the next essay
Week of 16 NovWeek of 23 NovWeek of 30 NovWeek of 7 Dec
Essay A post sharing the essay A new post from the essay Your readers hear from you three times a week, every week.
How it works

One article becomes weeks of posts

These articles are real. Pick one and press the button to see the ideas Pennywurth finds in it. Point at an idea to see where it came from.

Try it on
Unreliability · Substack · by Obakeng Mosadi

Visualizing Local Municipalities Spend with ClickHouse

What the article says, in short

At 10 million rows, ClickHouse ran the trend query in 40ms versus 354 ms for Postgres.

ClickHouse earns its place once MapMyCity ingests all 85 million facts; until then it's an extra service.

The profile income breakdown fails for Cape Town 2024, so MapMyCity imports the raw incexp_v2 cube instead.

Nelson Mandela Bay reports around R24bn a year in capital renewal for 2020 to 2023, then R0.7bn in 2024.

Read the full article ↗
Ideas will appear here.
Your voice

It learns how you write, from five things you've written.

Pennywurth shows you the habits it noticed, with your own lines as proof. You keep the habits that fit, and Pennywurth writes every post with them.

The film is finished. I decided that this week.

Both sentences share the same news. Pennywurth writes the first one.
Made for Substack and LinkedIn

Each post fits the place it's going.

LinkedIn
For two years I thought my short film wasn't finished. …more
LinkedIn shows about 140 characters on phones before “…more”. Pennywurth checks that your opening fits above it.
Substack Notes
“@ClickHouse” will go out as plain text. One link, no image.
Notes have their own rules. Pennywurth checks each one before it goes to Buffer and suggests a fix.
Your newsletter
Title Subtitle Body
Substack doesn't let apps publish for you, so Pennywurth gives you the title, subtitle and body to paste.
The editor

Keep every version of a sentence.

Rewrite a sentence as often as you like. Pennywurth keeps each version, so you can go back to an earlier one. Lines you cut are kept too, and you can turn them into posts later.

Pennywurth doesn't suggest posts while you write. It waits until you say you're done.

Try it: click the yellow sentence, or cut the last line.
Sample draft · Essay · Draft 6

Finished is a feeling

For two years I thought my short film wasn't finished. Every week I found something to change.

Then one night in March I watched the newest cut next to the one from January. Neither cut was better. They were only different.

Nothing I changed after that made the film better.

The film has been out for a month, and I haven't once wanted to open the project file.

Saved · No cuttings yet
You stay in charge

You approve every post.

  • Nothing posts without your OK.
  • Posts go into the time slots you already set in Buffer.
  • You can undo any send.
  • We don’t train on your writing or share it.
You're set until 16 Dec.

Go write the next one.

Your first essay is free. Sign in with Buffer, add five things you've written, and see a month of posts from the piece you're finishing now.

Start with a free essay