Black transparent modal alert on iOS, as seen in several apps

I'm looking for an API for a certain type of modal alert view (iOS), but I'm not entirely sure whether it's home-built or Apple-provided. It looks like a black transparent square, with rounded corners, usually one icon and a label below. For instance, it is used in the iPhone Twitter app. As observed, it only displays information momentarily and is dismissed when a state has changed (like "Loading" or "Posting").

Is there a pre-built API for this or is it custom b开发者_StackOverflow社区uilt? And if possible, when shared publicly, where can I find such a thing?

Any help is greatly appreciated.

Kind regards,

Reinder

MBProgressHUD is what you're looking for:
https://github.com/matej/MBProgressHUD

Apple does not reject applications using MBProgressHUD.