There is an overwhelming amount of material to read and keep track of. Is anyone using an on-line or cross-platform PDF/Ebook reader that syncs? In other words, in order to move between devices and spend as much time as humanly possible reading ( ) it would be ideal to have a service where you could either upload your pdf/ebooks and read them on-line (meaning you always know where you are in reading) or else a local program for phones/tablets/desktops which syncs reading locations and documents between instances.
Anyone already using anything like that? This must be a basic function and need of all college and post-graduate students and teachers today. I am sure there are going to be some paid services which may or may not be worth it, but the ideal answer is the closest thing possible to open source and free.
I googled and see some threads that I haven't started reading yet: