Two excellent resources from BookBub <info@bookbub.com> I use this app if I'm looking for inexpensive books to review and purchase. I use Amazon Kindle and download a SAMPLE first and if I like the content then I purchase the book. Very inexpensive at times. The "BE Series" books by Warren W. Wiersbe are commentaries and are very easy reading. I also like the writings of Lee Strobel and Mark Mittelberg; both are excellent authors and have other books that you can purchase as eBooks or paperback or even hard cover through Amazon and other warehouse book stores.