Well your app is crashing, can i see your code to help.

import "THViewController.h"

@interface THViewController ()

@end

@implementation THViewController

• (void)viewDidLoad { [super viewDidLoad];

  self.predictions = [[NSArray alloc] initWithObjects: @"It is Certain", @"It is Decidely so", @"All signs say YES", @"The stars are not aligned", @"My reply is no", @"It is doubtful", @"Better not tell you no", @"Concentrate and ask again", @"Unable to answer now", nil];

  //[predictions objectAtIndex:0];

  // Do any additional setup after loading the view, typically from a nib. }

-(void) viewDidAppear:(BOOL)animated { [super viewDidAppear:animated];

CGRect frame = self.predictionLabel.frame;
self.predictionLabel.frame = CGRectMake(frame.origin.x, 200, frame.size.width,frame.size.height);

}

• (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. }

• (IBAction)buttonPressed {

  int random = arc4random_uniform(self.predictions.count);

  self.predictionLabel = [self.predictions objectAtIndex:random]; //self.predictionLabel.text = @"YES"; } @end