Apple Store's app Activity Indicator

gistfile1.txt

    UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(20, 20)
                                                        radius:10
                                                    startAngle:-2 endAngle:3
                                                     clockwise:YES];
    
    CAShapeLayer *layer = [[CAShapeLayer alloc] init];
    layer.frame = CGRectMake(0, 0, 40, 40);
    layer.strokeColor = [UIColor grayColor].CGColor;
    layer.fillColor = nil;
    layer.lineWidth = 1;
    layer.path = path.CGPath;
    [view.layer addSublayer:layer];
    
    CABasicAnimation *animation = [[CABasicAnimation alloc] init];
    animation.keyPath = @"transform.rotation";
    animation.duration = 1;
    animation.toValue = @M_PI;
    animation.additive = YES;
    animation.cumulative = YES;
    animation.repeatCount = HUGE_VALF;
    
    [layer addAnimation:animation forKey:@"rotatation"];