Even as a free version user, I find this app very helpful for accessing my Dropbox-stored libraries. It takes advantage of some of the primary advantages I see to using Calibre, including tag searching and cover display. The biggest complaint that I would like to request some attention to is whatever goes on while the app is in the background. I’m usually using my Calibre libraries during research, which often requires juggling multiple apps. When in the background, The app resets to the home screen and disconnects from my cloud server. You can imagine how annoying this is. I do also have two feature requests. I have two libraries in Dropbox. It would make more sense to me to select which library to connect to from the home screen, rather than connecting and loading a library & then having to switch. This seems counterintuitive, and I am constantly hunting for this selection. There’s also a bug of some sort that always indicates the library I want (but which isn’t currently connected) selected, so I have to toggle twice to get it to actually load.Finally, it would be lovely if some additional search functions loaded, as I find Subject my most useful tool for finding references. Thanks for making this handy tool! I’d be happy to chip in for its development, if you could see your way to abandoning the subscription model. There are too many of those in our lives these days.