Books

https://play.google.com/store/apps/details?id=com.goodreads

Goodreads is like a social network for books, your ratings on books define what recommendations appear. Be aware that some categories are hidden inside the search and must be followed manually

https://books.google.com/talktobooks/

Experimental Project from Google: Ask your question and it will search for answers in books.

https://www.literature-map.com/

Skip searching books of the same category and explore writings of the same style

https://howlongtoread.com/

For those in a rush that want to know how long itll take to read the book