uhoh gotta go
Nearby toilet search and discovery service UhOh Gotta GO! is the quickest, simplest and best way of finding a public toilet, bathroom or restroom. It uses your device's GPS to find public toilets in your area. In addition, there is the option to search for any toilet or by simply clicking the direction button, it will navigate the user to the nearest toilet(s) within 500 meters without the need to search. It's free, no in-app purchases and has thousands of toilets in its database.
This app is now available on iTunes (App Store)