At Cpruce Labs we created iPhone games using geolocation services and mapping as part of the gameplay to  have users find and interact with game elements. Spectroscope was the first game we launched.

Spectrascope Description
I got the idea in 2011 sitting at a restaurant with misbehaving kids.  Thinking Christmas might motivate them to behave, I told them they were being watched by elves and that I had an elf detector on my phone. They called my bluff so I decided to build one.

Given it was only June, the idea quickly morphed into a halloween/Ghostbusters inspired app that would allow kids to track and capture monsters. Taking advantage of the GPS, the game would generate a list of targets with geospatial location near where the kids’ phone. Using the radar function in the app, the kids would physically track and get near the target and then try to capture it. Capturing it was a complex process of keeping the target in the beam using pitch and roll motions. Once captured, the type of monster was visible and points assigned. A simple concept, but forced the player to interact with their environment, rather than just sitting on the couch all day.

The next version of the application we were developing was going to update the radar function to superimpose the targets over the phone camera to create an augmented reality experience.