Nav Camera (US$3.99) is an innovative app that uses navigation, augmented reality and display overlays to tell you where you are, your altitude, the direction you are facing and more. The information appears on your image in real time and it's possible to save it all to your photo library.
Nav Camera is going to find a home with surveyors, engineers, architects, sportsmen, and military and police agencies. When you view your image in Nav Camera, it has a time stamp, position, altitude, GPS Datum and compass bearing. The app also supports custom notes, which can be a project name or any other pertinent information you want to add.
Using the app is easy enough. All the controls are superimposed over your live image, and you can select stills or video and make color decisions about the displayed data overlay. Nav Camera also features colored filters that are applied in real time to preserve night vision.
Certainly there are many other apps that will show your position and display other metadata like camera exposure information, but Nav Camera doesn't require another app to view the data -- it simply overlays it on your images.
This is not an app for the casual photographer, but people in some of the technical, military and law enforcement trades are going to be quite excited with the capabilities Nav Camera offers. I used it on a quick photo trip to document my location and time, then took my actual photos with my DSLR.
Nav Camera also offers one in-app purchase for $2.99 -- it's a datum pack that helps professionals get their location and altitude from the iPhones on-board sensors even more precisely.
The app is designed for the iPhone or the iPod touch and requires iOS 7 or later. I ran it on iOS 8 beta 5 without incident. There's a lot of power here, for not a lot of money.