Finding restaurants can be done with the same OpenStreetMap-based apps as navigation. I use OsmAnd all the time to find out where restaurants are.
But OpenStreetMap doesn't have a review functionality, nor is it trivial to add one from an external site to one. Apparently there have been efforts in this direction, but I don't know a lot about them: https://wiki.openstreetmap.org/wiki/Reviews
So I don't have an answer for reviews. But the review databases that currently exist are a manipulation battleground which people should take with a grain of salt anyway.