This is a good app, it reads pdfs and djvu files as promised and the file viewer is good. Unfortunately it needs more bells and whistles before being great: - Crop white space is greatly needed (a real deal breaker); - A favorite books list; - Tabs. I dont use cloud so I wont comment in that. Implement crop and I will give five stars. Meanwhile, I give it one star because is bugs me every time I start it to rate it.