Terrible Mushroom
An independent UK software studio. Mac apps for writers, paid for once.
Who is Terrible Mushroom?
Terrible Mushroom is a small software studio based in the UK. It makes Write 500 Words, a Mac app that helps authors finish their books, and supports the writers who buy it.
What's the ethos?
Built for one job
Write 500 Words helps an author finish a book, and that's the entire brief. Anything in the app that doesn't serve the manuscript, or the habit of adding to it, didn't make it in.
Plain markdown, on your own Mac
A Write 500 Words project is a folder of plain markdown files sitting on your Mac. Markdown is an open format with nothing proprietary about it, so your book stays readable on any computer, in any text editor, whether or not this app is anywhere near it. Or this studio, for that matter.
No account, no telemetry
The app never asks for an email address and there's nothing to log into. Nothing phones home. If the app crashes, the report stays on your Mac unless you decide to send it to support@terriblemushroom.com, and even then your writing isn't in it.
One purchase, no subscription
The app is sold once, through the Mac App Store. Pay once and it's yours on every Mac signed in to your Apple Account, Family Sharing included.
A book takes months, often years, and the place your manuscript lives shouldn't be charging rent for the privilege.
There's a 14-day trial first, so you can find out whether the app suits you before any money changes hands.
Apple Intelligence
The app itself uses Apple Intelligence in one place, a feature called Content Analysis. It reads your manuscript and hands back a synopsis, along with lists of the characters, locations, objects, themes, and timeframes you've mentioned so far, which is useful once a book has grown past what one head can hold. It writes no prose. It runs on-device, so the manuscript never leaves your Mac, and it can be switched off.
What the studio makes
The statutory bits
Terrible Mushroom Ltd is a company registered in England and Wales, number 17127662. Registered office: 82A James Carter Road, Mildenhall, Suffolk, IP28 7DE.