iOS icon jiggle algorithm

@Vic320's answer is good but personally I don't like the translation. I've edited his code to provide a solution that I personally feel looks more like the springboard wobble effect. Mostly, it's achieved by adding a little randomness and focusing on rotation, without translation:

#define degreesToRadians(x) (M_PI * (x) / 180.0)
#define kAnimationRotateDeg 1.0

- (void)startJiggling {
    NSInteger randomInt = arc4random_uniform(500);
    float r = (randomInt/500.0)+0.5;

    CGAffineTransform leftWobble = CGAffineTransformMakeRotation(degreesToRadians( (kAnimationRotateDeg * -1.0) - r ));
    CGAffineTransform rightWobble = CGAffineTransformMakeRotation(degreesToRadians( kAnimationRotateDeg + r ));

     self.transform = leftWobble;  // starting point

     [[self layer] setAnchorPoint:CGPointMake(0.5, 0.5)];

     [UIView animateWithDuration:0.1
                           delay:0
                         options:UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse
                       animations:^{ 
                                 [UIView setAnimationRepeatCount:NSNotFound];
                                 self.transform = rightWobble; }
                      completion:nil];
}
- (void)stopJiggling {
    [self.layer removeAllAnimations];
    self.transform = CGAffineTransformIdentity;
}

Credit where credit's due though, @Vic320's answer provided the basis for this code so +1 for that.

OK, so the openspringboard code didn't quite do it for me but I did allow me to create some code that I think is a bit better, still not prefect but better. If anyone has suggestions to make this better, I would love to hear them... (add this to the subclass of the view(s) you want to jiggle)

#define degreesToRadians(x) (M_PI * (x) / 180.0)
#define kAnimationRotateDeg 1.0
#define kAnimationTranslateX 2.0
#define kAnimationTranslateY 2.0

- (void)startJiggling:(NSInteger)count {

    CGAffineTransform leftWobble = CGAffineTransformMakeRotation(degreesToRadians( kAnimationRotateDeg * (count%2 ? +1 : -1 ) ));
    CGAffineTransform rightWobble = CGAffineTransformMakeRotation(degreesToRadians( kAnimationRotateDeg * (count%2 ? -1 : +1 ) ));
    CGAffineTransform moveTransform = CGAffineTransformTranslate(rightWobble, -kAnimationTranslateX, -kAnimationTranslateY);
    CGAffineTransform conCatTransform = CGAffineTransformConcat(rightWobble, moveTransform);

    self.transform = leftWobble;  // starting point

    [UIView animateWithDuration:0.1
                          delay:(count * 0.08)
                        options:UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse
                     animations:^{ self.transform = conCatTransform; }
                     completion:nil];
}

- (void)stopJiggling {
    [self.layer removeAllAnimations];
    self.transform = CGAffineTransformIdentity;  // Set it straight 
}