What is the best app to help me find good restaurants while traveling to foreign country?

You can check the Foursquare app for this . To be specific about Restaurants you can check Zomato it caters to some parts in the Asian subcontinent , this can be helpful 

Zomato (acquired Urbanspoon)

Yelp

Foursquare

Eat24

I think its good but cant say best...."UrbanSpoon".

Thanks for invitation 

FourSquare

Talabat

Yelp