Of the apps offered for this Thing, I downloaded Free Books. I had used it before and ended up deleteing it from my iPad. It has a great collection of public domain books. There are enough titles to keep you in books for years. I find the interface easy to use and intuitive. I have been finding the ads on the free site more intrusive lately. It seems that they are pushing their audiobooks which you can access "free" for a $3.99 access fee. Probably a good deal, but I am picky about audio books. I have to like the reader's voice if I am going to listen to them read for hours. I also don't have a way to pay for apps that are not free without urchasing them myself. My iPad belong to my employer.
I have discovered a collection of original Dr. Who stories that I am excited to try. They were written fairly recently so I was surprised to see them. Fun. I read science fiction and was happy to see some works by other contemporary authors included.
I will keep this app on my iPad over the summer and see how much I read.