WordSearch Bible offers a free eBook every Friday on their blog. The program you need to view these books is free on a PC, a Mac, iOS, and Android, and/or an account on the WSB web site so there is no reason not to grab these books. (They also have a for sale more advanced version for PC and Mac) There are also more than 200 free books available for download not counting more from LifeWay that will also work. The link above is to our wiki where there is an article on WSB. Some may like other programs better but I am very happy with this one, it does what I need to do and the books are usually cheaper than other programs.
Dale