I agree with everyone else, the Kindle app is great. I have it on my iPad 2, iPhone, and PC. There are programs such as Calibre that will let you change the format of eBooks to be read on other apps (ie, PDF to Kindle or vise-versa). When I buy a Kindle book I can read it on any of my devices and it will pick up where I left off so if I read to page 101 on my PC then a half hour later I read it on my iPad 2 it will go to page 101. Try it, you may like it otherwise convert your eBooks to formats that can be used on other apps (iBooks, Bookshelf, ect.).