Never be late to class again. http://devpost.com/software/speedup
SpeedUp has an arduino connected to a vibration motor and adafruit bluetooth LE shield that interfaces with your iPhone to select the pace required to walk to class on time. It's a handsfree solution: If your walking too slow, your shoes will start vibrating at the correct pace and will only stop once you get there; if not nothing happens.
This source code to connect arduino via bluetooth to your iPhone with Xcode 7, Swift 2, and iOS 9 was a difficult task involving alot of manual code conversion. So this code might especially be helpful for interfacing via Bluetooth LE to arduino.