Best for: When you're out and about and want to eat now.
How it works: Available for Android and iPhone, this app displays nearby restaurants offering immediate discounts (starting at 50 percent off). Show your phone's Scoutmob screen to your server to get the lower price.
Downside: You have to be willing to try an unknown place. The app focuses on restaurants that need business, not spots with buzz.
Average discount: 50%
Where it works: Thirteen cities, including Atlanta, Boston, Dallas, Los Angeles, New York, San Francisco, and Washington, D.C.