I'm going to take a moment to chime in on sync support.
Syncing across my tablet and phone is of undefinable value to me. I was doing so successfully using Dropsync from the Play store, and syncing all the .cr3 folders, but one of the updates in the last couple months has stopped that from working.
I've tried several other readers with little success. Moon+ is the closest to being tolerable to me, but it has such poor performance that I dread using it.
Any update as to when internal syncing will be viable in Cool Reader? Alternatively, any ideas as to how I can get my hackeneyed syncing with Dropsync to work again?