MotionManagerExample.swift

import UIKit
import CoreMotion

class ViewController: UIViewController {
  let motionManager = CMMotionManager()
  var currentAngle:Double!
  
  override func viewDidLoad() {
    super.viewDidLoad()
        
    motionManager.deviceMotionUpdateInterval = 0.1
    motionManager.startDeviceMotionUpdatesToQueue(NSOperationQueue.currentQueue()!) { (motion, error) in
      if let attitude = motion?.attitude {
        let interfaceOrientation = UIApplication.sharedApplication().statusBarOrientation
        if UIInterfaceOrientationIsPortrait(interfaceOrientation) {
          self.currentAngle = self.radiansToDegrees(attitude.pitch)
        } else {
          self.currentAngle = // TODO
        }
      }
      //TODO: Update Label that shows the current angle
    }
  }
    
  private func radiansToDegrees(radians: Double) -> Double {
    return radians * 180 / M_PI
  }
}