Purchased this for .99 via the App Store and PayPal. Apple charged me eight (8) times for the same purchase, but calling PayPal I was quickly able to get the proper credits.
(A week later Apple acknowledged the error was theirs by email).
I was excited by the then glowing reviews for this app, but after a few days use I found its use was making my Mac very unstable and have since stopped using it.
There is no such thing as a free lunch (or even a .99 one) so my advice is caveat emptor.