Mac software for
writers.
Terrible Mushroom is an independent software studio, based in the UK. The studio makes Write 500 Words, a Mac app built around the daily habit of finishing a book.
Write 500 Words
Finish the book, a day at a time.
Write 500 Words is built around a daily word count. Write your five hundred, or whatever number turns out to be yours, on enough days and eventually there's a book. The manuscript and all the notes around it live in one place while it happens.
Coming to the Mac App Store. Requires macOS 26 Tahoe or later.
How the studio works
Pay once. No accounts, no tracking.
Buy the app once and it's yours, updates included. There's no account behind any of it, nothing to sign up for and no email address to hand over. The studio collects no analytics at all either, which means nobody here knows what you're writing, how often, or whether Tuesday went badly.