Time left in chapter/book
The kindle has the extremely useful feature of figuring out how long you've got left in the current chapter or book (user selectable) at your current reading speed. Something like this would make it much easier to read through various books in your library and allow you to account for the amount of time you have available to read.
Andrew B commented
This would be nice for reading.
Terry Weiss commented
I definitely would love this or at least a percent compete
Steve Stanley commented
Yes, this would be great for both app and desktop. I hope Logos implements something like this!