Calibre might not be the most polished app in the world, but it’s definitely the best software for managing your ebook collection. It ticks all the right boxes: it’s free, there aren’t any ads, and it boasts a vast number of powerful features. Sadly, many of those features fly under the radar, which is a shame because they can elevate your ebook management to the next level. So, without further ado, let’s take a look at some of the best hidden Calibre features. Download: Calibre on Windows, Mac, and Linux 1.