Feather is a book-writing workspace that keeps a manuscript and its supporting notes together. Writers can draft in Markdown, organize chapters in a sidebar, compare two sections side by side, and track chapter word counts and status. A story bible stores characters, places, objects, and organizations, while notes can attach to specific passages. Proofreading tools check spelling and grammar in several languages and flag nearby repeated words or filler terms. The app exports to Word, EPUB, PDF, Markdown, or plain text, including formats for common book destinations. Feather is free, with no account or subscription listed. It saves as ordinary text files, but it requires iOS, iPadOS, or macOS 26 or later.
