on Just Publishing Advice:
Book writing software to help you be more creative and productive
Many new writers and authors start out using a word processor such as Microsoft Word or Google Docs. But word processors are not designed to help the creative writing process.
Word processing, spreadsheets and a desktop publisher are for commerce and administration and are not the best tools at all for creative thinkers.
When you decide to write a book, you would be much better advised to look for writing software that is more distraction-free and explicitly designed for writing a book.
There are a lot of software packages available for writers. However, some such as Scrivener, Ulysses, Vellum, ProWritingAid and even Word can cost you a lot of money.
If you are starting out, there are many free software alternatives that you can try. There is always a learning curve when you start using new software programs.