Here are two CocoaPods I really like for their simplicity, ease of use and impact:
1) Facebook’s Shimmer
Shimmer is an easy way to add a shimmering effect to any view in your app. It’s useful as an unobtrusive loading indicator. Shimmer was originally developed to show loading status in Paper.

https://github.com/facebook/Shimmer
Sample Code:
FBShimmeringView *shimmeringView = [[FBShimmeringView alloc] initWithFrame:self.view.bounds];
[self.view addSubview:shimmeringView];
UILabel *loadingLabel = [[UILabel alloc] initWithFrame:shimmeringView.bounds];
loadingLabel.textAlignment = NSTextAlignmentCenter;
loadingLabel.text = NSLocalizedString(@"Shimmer", nil);
shimmeringView.contentView = loadingLabel;
// Start shimmering.
shimmeringView.shimmering = YES;
2) MZTimerLabel
MZTimerLabel is a UILabel subclass, which is a handy way to use UILabel as a countdown timer or stopwatch just like that in Apple Clock App with just 2 lines of code. MZTimerLabel also provides delegate method for you to define the action when the timer finished.

https://github.com/mineschan/MZTimerLabel
To use MZTimerLabel as a stopwatch and counter, you need only 2 lines.
MZTimerLabel *stopwatch = [[MZTimerLabel alloc] initWithLabel:aUILabel];
[stopwatch start];
Easy? If you are looking for a timer, things is just similar.
MZTimerLabel *timer = [[MZTimerLabel alloc] initWithLabel:aUILabel andTimerType:MZTimerLabelTypeTimer];
[timer setCountDownTime:60];
[timer start];