what are good chess books?

There is an app called Forward Chess through which you can buy chess books and read them on your phone or tablet. There is also a library app called Libby that lets you borrow and read books online. I hope this answers your question.

I know lots of people use Kindle to download and read books, but I am not familiar with that.

Chess.com has a number of on-line courses so that's a good place to start. A membership level that gives you access to them is good value.

The "Winning Chess" series by Yasser Seirawan can be downloaded from public libraries, that could meet your criteria of being on-line.

Chessable.com has many good books/courses including ones by Yasser Seirawan. The free ones are usually a chapter from the paid version. The book versions, without video commentary, are well priced and they go on sale often.

Good Chess Books for Beginners and Beyond...

https://www.chess.com/blog/RussBell/good-chess-books-for-beginners-and-beyond

Scribd and PDFdrive For Online Chess Book Reading, Downloading...

https://www.chess.com/blog/RussBell/scribd-com-for-online-chess-book-reading

https://www.chess.com/blog/RussBell

Irving Chernev is a great author I would suggest any beginner books written by him.

This was a great one:

https://www.academia.edu/37149878/How_to_Reassess_Your_Chess_4th_Ed_Jeremy_Silman_

Too advanced for beginner-novice.

True I just read the post asking about books in general

thanks