JDCarouselControl is a subclass of UIControl which mimics some of the behaviour of UISegmentedControl in a visually different way. It's still somewhat crude so the functionality is rather limited, and don't expect it to be anywhere near bug-free.
You can change the ratio of the inner to the outer radius using the #define'd value; but make sure that the view placement radius is adjusted correctly. It isn't something you can change dynamically because I haven't found a quantitative relationship between the two. So if you change INNER_PROPORTION, make sure to play around with VIEW_RADIUS_PLACEMENT_PROPORTION such that the segment views are centred within the drawn segments. Just as the radius placement proportion is the ratio of the radius of the view placement to the radius of the outer circle, VIEW_SCALING_FACTOR is the ratio of the size of the views to the radius of the outer circle. This value seems to work for most of the use cases I've encountered.
Feel free to use without permission or attribution. It'd be nice if you let me know if you incorporated this into your project though :)