Spyglass
Yes, your iPhone has built-in Maps with navigation. But it can't hold a candle to the power of Spyglass. This beefy app was designed for outdoor and off-road navigation, giving you options for augmented reality navigation, the ability to navigate by the stars, the ability to save your custom places and waypoints, show them on maps and on the augmented reality display, and then navigate precisely to them later. Oh, and it also serves as binoculars, a compass, a speedometer, an altimeter, a rangefinder, and an angular calculator.