Google Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.

bibisco - bibisco is a novel writing software.

Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.

Scrivener - Scrivener is a content-generation tool for composing and structuring documents.

Wondershare PDFelement - All-in-one PDF editor

Gingko - Write and organize your ideas in Gingko tree documents.