AlertView? Alert? What is it?

I've seen some cool looking "windows" / "alerts" /whatever they are called. I wish I knew. Here's some examples of them:

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These shouldn't be Apple exclusive, since I've seen 3rd party apps use them! I'd like to know what are these windows?

Solution

It Custom UIActivityIndicator that you can found in this link

https://github.com/jdg/MBProgressHUD

MBProgressHUD is an iOS drop-in class that displays a translucent HUD with an indicator and/or labels while work is being done in a background thread. The HUD is meant as a replacement for the undocumented, private UIKit UIProgressHUD with some additional features.......
For mor information go to above Link

Thanks :)