Works well but beware

Does good B&W conversions — no complaints for the money it is a bargain. HOWEVER, when you view this on the Mac App Store you will get a nag screen prompting you to get version 2 and you can’t get past it any easy way. You can’t force quit (window is hidden), you can’t quit the app, you can’t even shut down your computer without agreeing to visit their website. Ironically I was just seeking information to recommend it to a friend. Sorry, MacPhun you lost me with this nagware.

Nasrudin about Tonality