I'm not sure exactly how this smartphone app makes money, but I believe it is still a free download. Waze is a fully functional, user friendly, social navigation system. I've used it for over a year, in Panama and Canada, and aside from it wanting to route me through some pretty dangerous areas of Panama City to save me time, I have had 0 complaints. In fact I love it.
By social, I mean in real time, you can send messages to other users, warn them of hazards, police, and accidents, and the system even monitors the speed at which the users are driving, so that it can calculate the fastest route for you.
The only catch is that you do need a data plan to use the app. This means that if you are just a visitor to Panama, you should have a sim card with a local data plan, otherwise it could get pretty pricey.
Waze is a worldwide app, so no matter where you go with your telephone, you can navigate with it.