title_body: Kindle "Time Left in Book"
upvoted_answer: When in a book, tapping in the very bottom left of the screen will rotate through LOC, Page, Time left in Chapter, Time left in Book, and off. When in any mode other than off, the percent completion will appear in the bottom right of the screen.
  
  This is based on a 7th gen Paperwhite with firmware version 5.11.1.1.