As an audio-industry professional with over a decade of production experience to my name, let me tell you a thing audio tools in general: you cant fix garbage. If your audio is totally ruined, this app (and all professional noise-reduction software on the market) will make your audio sound like its under water. Its a horrible effect, but you cant blame the app, and thats what 99% of the negative reviews on here are about.
This app can take great-sounding audio with an unfortunate swath of broadband noise and help clear up that noise, and thats all you could really ask a program like this to do. The fact that its so easy to use is brilliant—just highlight a section between words or sound you want in your work, and the app automatically does the rest.
My only wish-list items for this app is that it would be swell to have some control over the noise reduction. Also, being able to import just audio would be handy. Finally, Dropbox integration would be a real plus.
All things considered, its hands-down the best app on the market for what it does.
Pedeclaudo about Denoise - audio noise removal