This is the worst case of NAGware I've ever seen! The registration window says it will remind you "from time to time to register."
That "time to time" works out to every 5 seconds!
When unregistered, the process only runs for 5 seconds before it stops and displays a registration nag screen. You must wait the designated amount of time before you may proceed: 1st pause=5 sec., 2nd pause=10 sec., 3rd pause=15 sec., and every pause after that is 20 seconds. So after running for 5 seconds, you must wait 20 seconds before you can run for 5 more seconds! Then, even though the process starts again, it provides an extremely annoying uh-uh sound when you press the Continue button. Maybe the registration screen pops up after a certain number of tracks have been processed, but it worked out to every 5 seconds for me.
And don't you dare go try to use another app while it's running, because in 5 seconds when it's time to hit Continue again, the icon begins bouncing in the Dock, making you want to punch the screen. I have now disabled Dock icon bouncing.
I didn't get to fully evaluate the app, because I don't have the patience or time to sit here pressing the Continue button every 20 seconds, and I'm not not gonna waste time making a script to do it for me.
I'm giving 2 stars for Features, Value and Stability just because I have to provide a rating to submit this review. They may merit 5 stars, but there's no way to tell since I couldn't test the app.