LibreOffice is my office suite of choice for writing my novels. As I write, I try very hard to not repeat words and/or phrases within a paragraph or adjacent paragraphs. However, it's not always easy to look at a document with the naked eye and get a solid grasp of the overall picture.
More LibreOffice: Page Number Wizard Setting the next style Accessibility Check Using different languages
What words have I used the most within a manuscript? That's an important question to ask