Here are a couple of apps that I have found useful:
Degusta - the Panamanian equivalent of Yelp. You can search restaurants by location, type of food, proximity to you, etc. It has ratings and prices as well. It is all in Spanish, but is pretty easy to figure out.
Waze - a gps app that works fairly well. It has turn by turn navigation and generally gets me somewhat close to where I want to go. A nice feature is the ability to see where you are on a map. When you are hopelessly lost and people are honking at you, at least you can get a sense of where you are in the city.