This is a a circular progress bar that i did for an iPhone project. The progress bar uses core graphics so it is very customizable. As you can see on the screen image, you can change the size, colors and everything. Also, since it is using core graphics to do everything you could tweak it without many issues, for instance, you could add some animations to the progress bar.
Here it is:Circular Progress Bar. The zip contains the circular progress bar component and a demo project.
Also, if you are interested in doing IOS components i recommend you to check PaintCode out (this is an affiliate link) This tool allows you to use a designer, similar to paint, to create the core graphic code. PaintCode is very expensive in my opinion but, for me, and probably for you as well if you want to use core graphics, it worth it.
This is my second post :). I Really know that i have to get better on this, but if by any chance you liked it or it helped you, please share and comment!!. [sdonations]2[/sdonations]