Have been using this app for a few months with no problems until yesterday. I finished My Ántonia and then everything disappeared. All four of my completed books were no longer there. I had planned to reread a portion of My Ántonia, but that obviously became impossible. My best friend said the same thing happened to him. Luckily, I had just completed a book; had this happened mid-way through it would have been much more frustrating (not like getting and illness or losing your religion frustrating, but certainly maddening within the context of the app experience).
Until this happened I loved the app. I still do, but I guess I am cautious. Now I am hesitant to start a new book.
Because of my enthusiasm, at least ten others are using the app! I hope you guys can fix this. Perhaps saving progress in the cloud?