I got the free version and used it as a document-management system for my various PDFs. It works OK at that.
The paid version, however, just crashes when I try to open documents, or I get the spinning beach ball that never goes away. Tabs also stay open and cannot be closed.
Also, opening the app from the dock requires a double-click instead of a single-click. (That’s a nitpick, but it’s those kind of oversights that sink the application.)
As a document reader, I’m better off staying with the free version. Although it boasts fewer features, it at least works. The paid version is unusable due to the nonstop hangups and crashing.
Like the other reviewers say, I can see the potential — it just needs work. Until then, this is a no-go for me, and I regret spending the money.