POLAR

I used to use Polar Bookshelf before, when it was still open source. It was very easy to use, however, I don't know what happened now, the open source version was gone, and the new Polar 2 and Polar 3, there are no update of it any more, and I am really want to know what happened behind it.

This is a convenient app, but my reading position is not restored. An option "Automatically resume reading position" is enabled in settings.