Ask HN: I'm implementing a progress bar – could Apple reject my App, then?

I'm totally new in the iOS App Store and not so familiar with Apple's rules or the US DMCA, either... I want to develop an App which shows a radial progress bar, similar to the one in the iPhone App "Activity" (looks likes this: http://pablomolnar.github.io/radial-progress-chart/ ).

Could I get in trouble regarding to Apple's rules, DMCA or even software patents?

Don't get me wrong, I don't wanna steal their design, but just reuse it. So the users aren't confused by multiple designs for the same thing.