Vegman (Free):
I’ve heard of Veg Out, but from what I understand, they are both essentially the same thing and this one’s free. Plus Veg Out had some awful reviews. Basically, call this the Yelp (another great free app) of Vegans and Vegetarians. It uses your current location and finds vegetarian and vegan friendly restaurants in your area, with their distance from you and reviews. I’m having dinner in the city with my mom tonight, and totally plan on using this.
http://pursuitofhippieness.com/2011/11/09/the-best-apps-for-healthy-living/

2. VEGMAN - Best for: Meat-free dinners
Attention leaf eaters (carnivores, close your ears). Dining out when meat’s not on your menu is no mean feat, especially if you’re in an unknown land. Using GPS, recommendations and reviews, Vegman collates a comprehensive list of vegan and vegetarian restaurants in your area, as well as veggie friendly eateries should you be dining with animal eaters.
http://www.shortlist.com/tech/10-food-apps-you-dont-know-about

Vegman - Worldwide Vegetarian and Vegan Restaurant Guide
The last app on our list of vegetarian apps for the iPhone will not tell you how to become a vegetarian per se, but will rather help you in finding vegetarian and vegan restaurants in your area. Of course, it also tells you how to get to those restaurants.
The app also serves as a companion app to the vegman.com community site. It lets you enter information about vegetarians you've met and you can like their profile on the community site. For a free app, Vegman for iPhone is definitely worth the download.
http://www.brighthub.com/mobile/iphone/articles/121641.aspx