Atticus Authors on Windows or Chromebook who need book formatting. Price: see official site
Draft2Digital Going 'wide' beyond Amazon. One-time $20 activation fee for new publishing accounts; $12/yr maintenance if under $100/yr in sales (waived first year); earns mainly via commission
Kindle Direct Publishing Publishing on Amazon and Kindle Unlimited. Free to publish; up to 70% ebook royalty
Reedsy Studio Free ebook/print formatting in the browser. Free; premium Studio Essential $4.99/mo or Outlining $7.99/mo
Vellum Mac-based indie authors producing ebook and paperback editions from one file. Vellum Press $249.99 (tax not included)