CounterLayer.m

@interface CounterLayer : CALayer
@property (nonatomic, assign) NSInteger count;
@end


@interface MovingCounterView : UIView
@property (nonatomic, strong) CounterLayer   *counterLayer;
@end

@implementation MovingCounterView

#pragma mark - CALayer Delegate

- (id)init
{
    self = [super init];
    if (self) {
        [self.layer addSublayer:self.counterLayer];
    }
    return self;
}

- (CounterLayer *)counterLayer
{
    if (nil == _counterLayer) {
        CGRect frame = CGRectMake(0.f, 0.f, 25.f, 300.f);
        _counterLayer                = [CounterLayer layer];
        _counterLayer.contentsScale  = [[UIScreen mainScreen] scale];
        _counterLayer.frame          = frame;
        
        // here we make sure we got informed
        // when our layer animates
        _counterLayer.delegate       = self;
        
        _counterLayer.contents       = (id)[UIImage imageNamed:@"SomeImage"].CGImage;
    }
    return _counterLayer;
}

- (void)startMarkerAnimationToYPosition:(CGFloat)yPos duration:(CFTimeInterval)duration
{
    CAMediaTimingFunction *timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

    // position animation
    CABasicAnimation *posAnim = [CABasicAnimation animationWithKeyPath:@"position"];;
    posAnim.timingFunction = timingFunction;
    // configure the posAnim as usual
    [self.counterLayer addAnimation:posAnim forKey:@"position"];
    
    // moving count animation
    CABasicAnimation *countAnim = [CABasicAnimation animationWithKeyPath:@"count"];
    countAnim.fromValue      = @(0);
    countAnim.toValue        = @(200);
    countAnim.duration       = duration;
    countAnim.timingFunction = timingFunction;
    
    self.counterLayer.count  = 200;
    [self.counterLayer addAnimation:countAnim forKey:@"count"];
    
}

#pragma mark - CALayer Delegate

- (void)displayLayer:(CALayer *)layer
{
    if ([layer isKindOfClass:[CounterLayer class]]) {
        NSInteger currentCount = [[layer.presentationLayer valueForKey:@"count"] integerValue];
        // update a text with this value
    }
}


@end



@implementation CounterLayer

@dynamic count;

+ (BOOL)needsDisplayForKey:(NSString *)key
{
    return [key isEqualToString:COUNT_KEY] || [super needsDisplayForKey:key];
}

@end