When iOS 5 launched in October 2011, one of the features that caught my attention was location based reminders. Location based reminders provided the ability to connect a specific reminder to a specific location. An example could be, written in English, “When I arrive at the supermarket, remind me to buy flowers for my wife” or “when I leave work, remind me to call Fred”. When you approach a supermarket a reminder pops up telling you to go get flowers or when I leave the office, I get a reminder to call someone on my way home. Although GPS/location features have been available for most generations of the iPhone, mixing that power with context can make your app very powerful.

Of course, geofencing isn’t only for the built in reminders app that shipped with iOS 5. Apple has opened it up for developers to access. Today, we’ll be looking at how to work with geofencing which specifically uses the CLRegion Class as well as the CLLocationManager. A good place to start, as always, is the class reference. If you are unsure how to understand class references, methods, passing messages, properties etc… then take a read of this post and return back when done. [Read more…]