I have this app on my iPad, and when Im reading at home, it works perfectly for what Im doing. I have a bunch of e-book PDFs sent to me by a friend, which I uploaded to my Play Books library through my PC and then downloaded through the app to my iPad. All of the books look great in the app. However, the minute I am out of wifi range, my books are nothing but a series of white pages, and my library page indicates that they need to be downloaded again. My iPad isnt data-equipped, so Im basically restricted to reading when Im in range of a wifi signal. This is infuriating, and Im strongly considering moving to another app if this problem isnt fixed.