Simple Words is described as 'easy-to-use yet robust word processor with a modern user interface, Rich Text processing, and compatibility with all popular file formats' and is a Word Processor in the Office & Productivity category. There are more than 50 alternatives to Simple Words for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and iPhone. The best alternative is Notion. It's not free, so if you're looking for a free alternative, you could try LibreOffice - Writer or ONLYOFFICE. Other great apps like Simple Words are Google Docs (Free), Microsoft Word (Paid), Manuskript (Free, Open Source) and WPS Office (Free).
LyX is a document processor that encourages an approach to writing based on the structure of your documents (WYSIWYM) and not simply their appearance (WYSIWYG). LyX combines the power and flexibility of TeX/LaTeX with the ease of use of a GUI.
AbiWord is a free software word processor. The name "AbiWord" (pronounced "Abby Word") is derived from the root of the Spanish word "abierto", meaning "open". It runs on Linux, Mac OS X (PowerPC), ReactOS, BeOS (unsupported), AmigaOS 4.