No Delivery on Implied Function

All this app does is display the desktop version of your webpage in a narrow window, alongside the full width version.
Activating the Developer menu in Safari preferences and then choosing iPhone display will atleast give you expected menu/content changes for a mobile device (and at no charge). It would have been worth $5 to see the two versions side by side, properly, but as it is, this app is just a waste of time.

If the developer included screenshots of the the app displaying a webpage maybe I would not have purchased—seems a little deceptive to me.

tqroofer about Duo, v1.0