I currently have a great thirst for reading up all sorts of Mathematics/Physics textbook which I have obtained as PDF files on my Nexus 7. I currently use two apps to use to books. These apps are Adobe Reader, and aldiko. I feel like these apps aren't good enough for organizing and locating the textbooks. I have so many on it already and I feel like these free apps aren't efficient. If anyone is interested in teaching me new ways to study using these PDF files on tablets with using a better app or anything related I would really appreciate it. I have also added pictures to show you how frustrating it is to switch between these books and learn using the tablet.