Use this application to help you walking straight. Why? Because we can't walk straight.
Put a blindfold on someone, take them to a park or a beach or a meadow and ask them to walk for as long as they can in a straight line. Then watch what happens: people walk in circles when not having a reference point.
This application relies on the compass of your cell to keep warning you of the direction you choose to walk.
Nothing fancy, but works.
Good for scouts, fan of wild, or just to have when going to a place where there could be no reference, no cell sign, and no GPS view.
You don't even have to keep looking at it. It will talk to you. Give it a try.