I have loved to read since I was little. I would borrow many books from the library and still borrow to this day, but I also purchase books (mostly for my kids) and freebies on Kindle. I read as much as I can daily. Sometimes I read several books at one time. I don't have a preference of paper book over an ebook, I just love to read. Keeping lists of what I have read is a good way for me to remember.
Yes, these books are all on Kindle. Yes, these books were all found and purchased for free. Yes, the ones that list as grade levels have some really nice photography. Yes, they have some really good, but sparse information. They just did very simple information and again I feel that the books are too simple and too easy for the grades listed.
If you have younger kids, these might be good starters.