[andhistablet]

I would like to have my entire library of thousands of books available on my iPad. I could use Send-to-Kindle (slow process) or the Calibre server. The server process is nice when it works but has not been totally reliable and requires me to be on the same network as my PC.

Since there is no easy way for Calibre to recognize my iPad with a physical connection (correct me if I am wrong), the easiest way that I have found to add books is to export from Calibre to folder on a flash drive. That drive, once connected to my iPad, can open the files and also save to iCloud. Recently I have been opening epubs on demand in iBooks, which automatically backs up to iCloud.

I am open to any suggestions on improving this process, but here is my primary question: When I export files of all of my books to another folder, is there any way for Calibre to indicate which files are NOT in that folder? Essentially, if I add 5x new books to my library later, is there a way to ONLY copy those new books to an external folder or tell me that they are not "on device" (flash drive)?

If I connect a Kindle, Calibre is aware of which books are not "on device" and indicate them clearly. Is there a similar way for Calibre to report which files do not have duplicates in another directory? Thank you in advance for all of your help.