Ever since I discovered goodreads I've been almost obsessed with tracking what I read and obtaining as much stats as possible.
At first, to get real time insights in my reading progress of books, I looked into extracting information from my kindle. Whispersync syncs the progress of the books I'm reading to something at Amazon. However, there is no public API to get this information out. I actually tried sniffing the traffic and using phantomJS to extract stuff from the cloud reader. But this all felt a bit hacky.
However, this all changed when I switched to reading my books with librera on my Android phone. (I switched to reading on my phone because I have it with me all the time)
It can sync your reading progress to Google Drive and after a short examination of the files stored on Google Drive I found out it was simply storing JSON.
Example of this file: