Does MotionX-GPS require a cellular network?

The iPhone 5, 4S, 4, 3GS and 3G use an A-GPS (Assisted-GPS) chipset which uses cell tower triangulation to speed up GPS signal acquisition. Cellular coverage is not needed to acquire a signal, however the signal acquisition will be much quicker if you have data coverage.

Without data services, it can take 15 minutes or longer to acquire a signal. This is simply because it takes longer to determine which satellites to use out of the 31 available around the world. With data services, it typically takes under a minute, but it can take up to 5 minutes.

You do need data services or WiFi if you want to share your waypoints or tracks via Facebook, Twitter or Email.