I downloaded the app and chose Florence as my free city since I thought I could do a pretty good comparison with the app versus what I know. If Florence is any indicator, the app's listings are pretty good. Somewhat narrow in the sense that it's missing some strong, authentic local options, but that's fine given that the list it does contain is very solid and contains no tourist traps or ...... restaurants known to me.
You might not pay $2 a city if you're sitting on your couch daydreaming, but if you're heading to one of these places, it's a small price to pay for a good, biased-in-the-right-direction list of restaurants near you.