Foursquare Swarm: The Check In App
Over on The Sweet Setup, Swarm by Foursquare was chosen as the best location logging app. It's fast, fun to use, and very accurate. Swarm's familiar design will make it easy for almost anyone to use. It has pin-point accuracy, great social integration, and fun gamification features.
You can download it for free on The App Store. You can read the entire review on The Sweet Setup