Observe and notify user if app has moved

gistfile1.m

// Observe and notify user if app has moved:
[[NSNotificationCenter defaultCenter] addObserverForName:@"AppHasMoved" 
  object:nil 
  queue:NSOperationQueuePriorityNormal 
  usingBlock:^(NSNotification *note) {
    // Check if we've already told the user recently
    NSDate *appHasMoved = [[NSUserDefaults standardUserDefaults] valueForKey:@"AlertAppHasMoved"];
    int interval = 7*24*60*60;
    if (appHasMoved == nil || 
    [appHasMoved compare:[[NSDate date] dateByAddingTimeInterval:-interval]] == NSOrderedAscending) {
      // Store in defaults
      [[NSUserDefaults standardUserDefaults] setValue:[NSDate date] forKey:@"AlertAppHasMoved"];
      [[NSUserDefaults standardUserDefaults] synchronize];

      // Present popup
      RIButtonItem *cancelItem = [RIButtonItem item];
      cancelItem.label = @"Later";
      cancelItem.action = ^{
        [[Mixpanel sharedInstance] track:@"Dismiss Moved App"];
      };

      RIButtonItem *downloadItem = [RIButtonItem item];
      downloadItem.label = @"Download";
      downloadItem.action = ^{
        [[Mixpanel sharedInstance] track:@"Download Moved App"];
        NSString *url = [note.userInfo valueForKey:@"new_app_location"];
        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:url]];
      };

      UIAlertView *alertView = [[UIAlertView alloc] 
        initWithTitle:[note.userInfo valueForKey:@"app_has_moved_title"]
        message:[note.userInfo valueForKey:@"app_has_moved_message"]
        cancelButtonItem:cancelItem
        otherButtonItems:downloadItem, nil];
      [alertView show];
    }
  }
];